DXAffinity

The one I am looking at is the Series Intuos PRO Large PTH-860-N, but for a similar price point there is also the XP-Pen Artist16 Pro 15.6 Inch Drawing Tablet Graphics Pen Display FHD IPS Monitor 8192 Pen Pressure with Shortcut Keys & Adjustable Multi-angle Stand, which from readers reviews and Q&A indicates people are using it with Affinity products.
Though I think XP-Pen Artist16 Pro is penned against the Wacom Cintiq 16 
 
Choices, choices, choices.

thanks for the wealth of information. 

And it arrived today! I’m looking forward to putting it through its paces quite soon.
Thanks to @firstdefence for alerting me to the attractive features (not to mention the very existence) of this lovely piece of kit. 

Many thanks. plenty of good points to bear in mind. 
I am putting 2-3 hours daily, currently mainly going though various Affinity Designer and Photo courses.
Loving it as I get used to it. 

Well, a screen protector is for screens.. but  there are films for classic tablets, too (a total must is that it'd EXACTLY match the exact dimensions, usually if the model is officially supported in the product specs!). A heavy hand sketcher MUST get one of those, surely no matter what brand or model. IMO is more important to worry about putting soft nibs, though.
A light sketcher, as you seem to say you are (although that concept is relative, some people think they are but actually put quite some pressure) doesn't need at all to add a protector. By any means. In the times when I believe Wacom got more complaints is in the gen of Intuos (Pro) 4 (not called pro, then, just marketing gimmick, If I recall well... but ofc was the pro range)  coming from the great Intuos 3 glass.... as Wacom supposedly wanted to give a bit of resistance to approach a paper feel, and a lot of people rumored it was just to give the product not such a long life (as much as I think the Paper model, is a vehicle to sell Wacom's specific Ink, in this case that other suspicion was a stretch), so to have a reason to purchase a new one. Wacom does not have there its selling point (not in the business of producing "fast food"), but indeed in deluxe quality. So, I realized soon enough that it was like always in the net : The ones complaining make more noise than a *huge* mass of happy users.  You "see" the negative ones, you don't see the positive noise as much (happens exactly so with Affinity products, BTW). Also, an stats' fact. There's as much variety as stars in the sky. So, yep, they were completely honest , those users, when telling what happened to them. As I saw videos, and read many complaints... Statistics say no matter what should be an average care for a device, you will find always extreme points and a a lot of shades of grey in between those extremes. So, there are people that draw and paint over a wacom like when they scratch a pencil (or carve stone) breaking the tip even over wood or paper.... Those will have no freaking tablet sturdy enough, on earth.
Now, that said, the surface of a wacom tablet is not any more like the beautiful glass one in the Intuos 3 gen, which was a really good and durable set of devices. Those were really solid.
You need to use a soft tip (you can easily replace the tip it comes with. It is really EASIER than it looks like). As the default one, I notice in the second day that was MUCH more likely to produce scratches (is too hard!! ) than the softer one. It actually also produces a response to touch that I quite prefer (like a brush/felt pen, or at least a 5% of that feel). is not the felt one, I believe there's one like a felt. I just use one that is quite plastic, but quite smoother than the hard plastic that comes installed in the pen as default.
If you just make the SOFT tip slide over the tablet, -no need to become either paranoid about it, BTW-  well, then... doing so I have not scratched this much softer-surface Intuos 4 XL, not a single visible scratch in 11 years. There are microscopic scratches, surely, you can see them if put your head at table level and see with a light source in certain angle.  They do not matter at all. They do start to matter if you make a DEEP scratch where the pen does bump when passing over. They could also matter if, not being any of that nature, you usually press enough to have make like a central area in the tablet more "rough", like "textured", due to bazillions of micro scratches of  certain importance. Still would be functional, but not as pleasant. Unlike with a deep scratch/crack, the tablet with those zones will last functionally yet many years. Now, I've seen those. And I know how crappily a user puts pressure on a tablet by seeing his/her tablet, at a glance. A light sketcher wont ever produce any of those damages on the surface. My 11 years is with most days full day painting (and often large part of the night) ! and is almost 100% as new.
Do not even worry if you are a light sketcher, I mean, after putting the soft nib. You would RATHER prefer to replace a nib than wreck the tablet.  A new pen is not that expensive, or a new set of nibs. And I'm YET using my second nib of the 8!   
Seriously, don't overthink it, just put that soft nib (no need for a tablet protector, IMO, and putting that can bring other probs...Besides, not easy to put WELL, there are risks) and don't press too hard. It'll become your automatic habit, you'll just draw and paint lightly and wont need to worry about it. After all, the usual pressure levels are really sensitive, that is, with light pressure you already get too much response (with the most extreme values that are yet useful for all  uses), so, getting subtle is also good for control reasons.
IMO, focus on getting control of the device, rather than not using it fully for fear to scratch it. It is WAY worse if you learn to use it even a single bit less due to fears, than actually scratching it (which wont happen if you aren't heavy handed) . Make a A LOT of exercises just drawing spirals, fast circles, parallels, long curves. Not worrying a single bit as you wont get them even slightly good at the beginning. But all those cr4ppy exercises will train the hand-screen coordination way faster than full pieces over years. A good thing is to do those exercises (I don't have a good link for that now)  like 15 -20 mins a day , then switch to making an actual project. After all, is all about working with it. For me is now like a glove, it just fits and works perfectly.
Sorry if you are an experienced tablet user or knew all this. One never knows...
Oh! Also, do NOT have any issue in setting the Photo, Krita, Photoshop, Corel Painter, Clip Studio Paint, or whatever your software is (and having the feature, all these have it)  with stabilizer ON. Do so. It makes getting the control of the lines A TON more enjoyable. U'll get there (being able to draw steady lines without stabilizers) anyway, but a fantastic method is to start with the level of line stabilizer that you'll need for functional and good quality lines for your projects work, don't be shy if need a high value, then go diminishing as you notice you go gaining control (and pushing a bit everyday, as if you get comfy in a stabilizer level, you don't improve in that)  over the lines. At some point you are able to fully disable the stabilizer (I wouldn't do so for zoomed-out in photo, tho). If you would never get comfortable enough to put the stabilizer off, that's 100% fine, too (the important part is that making art).  In the first place, it wasn't/isn't your fault. Because digital tablets , no matter if screen based or classic  -they both use a very limited magnetic grid-  do NOT have the level of accuracy your hand has (yeah, not even the cintiqs!!!). They add several factors that are what people notice, while being quite more accurate with a charcoal, pencil, or oil brush over canvas. So, nothing of this (line stabilizers) is "cheating", is just compensating for hardware having not reached yet the level of accuracy we humans have, as of yet. You are only approaching a bit to the control you would have with traditional media. If you go like I did, diminishing the stabilizer value, it means that simply your brain, and hand-screen (with classic tablets, as is a non issue in display-tablets, but this way you train for any situation, and become MUCH better once you handle a display-tablet, if ever do so) coordination is getting more used to it, not that you are becoming a better artist, just used to a new machine and its shortcomings.
Answering more specifically, nope, scratches, by a light hand sketcher, not easy/probable to be generated.
Easy to remove, a deep scratch : Not that I know. There might be a way, but I don't know any. And applying some product to it, or polishing the surface I'm afraid can lead to a quite, quite worse situation. I had to put on the shelf my lovely Intuos 1 A4, which had traveled with me through several game companies, just 'cause a total idiot happened to get drunk or sth in a company party, and sadly I wasn't there at the moment....  The guy (surely with help) really did sth nasty to produce those scratches. I still have it as a museum piece, and... well, you CAN use it, but the pencil will jump over those deep scratches, is not functional anymore. 
I have worked at many companies, be it games or software/agencies, and have used bestbuy tablets,  genius tablets,  Kurta, Summagraphics, Wacom volito, Wacom graphire, Wacom Bamboo, Intuos of several flavors. Never produced scratches. So, I might be saying that for certain type of user, scratches are NEVER an issue. They simply wont be created with really proper handling. It does not get scratched by a bad glance or something, lol.
Now, if you have kids or cats... yeah, totally different scenario.... is like having mates at a company that can't behave.... Just that you can't blame the former ones, and can't either have real control over the latter. So, better have the tablet ALWAYS out of reach of beasts of any size .....  

To get an in-depth conclusion, I'd at least give it a full month of heavy training (at least 3 hours per day).

My thoughts exactly. Thanks

Ok I will avoid 2nd hands then. Better be safe, and I need one for the long run.

Ouch... I would not buy a Wacom second hand...you never know how the user treated it...
In the other side, if you have strong trust on the source which is selling it to you, are very sure you can ask for full refund and not be charged on shipping, it can be worth the risk, as one thing about Wacom is that they're darn durable. IE, if I'd have to sell my XL now (never will) I'd have my conscience 200% in peace by doing so, as I'd know it's in pristine state despite having produced tons of works in decades with it. Maybe a Bestbuy or Genius from that time would be broken in someway (or hardware recycled) at this moment in time.
Your budget is several times past the non paper (BTW, the naming for the paper model is with a -P, if I'm not wrong) one... I'd buy first hand to get the Wacom's warranty and all. And also have the peace of mind that it will come perfect (they'd send you a new one at no charge if anything is wrong. Which might happen more with cintiqs, and a lot more with Companion/Studio, but with the classic tablets is extremely rare to happen).
That is... I would personally go for the original first hand thing.
If you are asking if going for an older model not the PTH-860 ...Hmmm... neither I'd do that (if anything, a second hand L of THAT model) . Because is the gen that has come with pro pen 2, 8k pressure levels and a ton of other tracking and other improvements. Many that add up. (ie, a huge difference between my Intuos 4 XL and this model, the current L being much better than mine in every single area).

Many thanks, it has helped my a lot understand the various Wacom offerings.

Seems it refers to "North" and -S to "South" (when it's tablet-whatever-S. Don't confuse when refers to tablet size, with a space, ie Intuos Pro S ). And that most prolly means the region of commercial distribution... probably hemisphere wise, or some other distribution. Seen it without the distinction in many places. It's....IMO  the totally freaking same tablet, to all what matters. The Large: PTH-860 , which is all what matters. Most probably, the region has its influence in the drivers and software being offered in a set of languages or another.  For some countries this can be crucial. If you are fine with English text in drivers, you're fine in any case. Anyway, th software included is of no super great value for any pro or advanced hobbyist, and anyway, u'll download the drivers, the most current or a version that is not imcompatible with A or B software, as ain't true that Wacom produces always faulty free drivers. Typically the latest one is best.
The LA (latin versions in many hardware devices, wacom and whatnot) versions, or other produced for regions of the world not being EU or US/Canada "can" come with some traps, in the sense that some of those versions are actual re-launch of older tablets, that are pretty fine, but sold as current, while is older tech, so that they can sell too in markets where the economic capability could be lower. The issue is that these are often mixed in Amazon , and u might be fooled by the low price. An example of the LA and a similar case with another similar situation sold in India, some time ago, was actually a "refurbished" (not really, was an official product) previous bamboo, so to sell medium size tablets in those regions at a competitive price there. This will not happen as often as the regions are growing/developing.
A Large: PTH-860 anyways, is the real (current at time of this post) L thing. With or without -N. Now, a dealer can wreck things badly and sell a small size as a Large PTH-860-S , so, indeed, I prefer if I see not letters attached. It'd be rare to happen, tho. But happens in the best places (you can always as for get the right one with no shipping charges after the fact, usually) . I got as first hand this now arcane XL as the 'DTP' (as they wanted to make a distinction per professional fields : CAD vs 2D graphic design, etc) model, while , even being a local shop, they actually game me the CAD model. I liked a lot the cad mouse, so didn't went back to the shop    . In the end I did not use the mouse at all, to avoid any scratching possibility of the surface. The two tablets function just the same. This happens often among two exact main models.
 

My preference : 3,2,1. Unless you BADLY need a mobile sketching platform on the go. In that case nothing beats the iPad pro. UNLESS... would be for painting under strong sunlight. For line-art inking/pencils on a Starbacks or whatever the, er, safe pub, it's really good. For getting you first a solid work horse, nope, that keeps being my 2c. That's the Wacom L, IMO. The XP-PEN 22E would leave you a lot of money for other matters. Even getting your self a Deco 03 (or their Deco Pro thing), so you'd get a classic tablet for hours or days where you can't stand the 8 hours smashed to the screen. Indeed, XP-PEN + Ergotron arm + Deco 03, and ur still not over the budget... The Deco 03 is pretty functional. Just that the precision of the Wacom L is imo a wet dream for illustration. So, the W. L and the 22E : Close match, as with 900 pounds u get a lot of extra money to get you a decent medium size classic.

I for sure would get me  the Wacom L.  And that said I don't disagree with Scungio in the way that could be said that iPad pro is an EXCELLENT companion (not a full replacement...so....getting it without having yet your workhorse....). Once one has the workhorse, and for me this is both in the computer/processor/OS matter, and also in the sense of having a tablet that lets you work 10 hours easily without ergonomic damage (or minimized). Specially through the months/years of steady work. Anyway, I recommend not to go over 8. In final delivers I've gone in 20 hour sessions (a note for other readers, not us three...). I've learnt not to that anymore, EVER. No matter what. Having worked steadily with a Cintiq 12 WX (12 inches screen, so, too) professionally for some months short of a year, I can very safely say that that size is NOT for 8- 10 hours of continued work , though even just months. Not for the screen, neither for the tablet. There might be people -many- saying otherwise: We'll check how's health in 5 -8 years. :s . And not that I wish anyone  getting a health prob! lol. Not even getting a light cold. But is like everything, and in that I fully agree with Scungio:  If considered a companion after getting your workhorse solution (IMO, a Ryzen or Mac with good specs + a classic tablet), then both a display-tablet (the top 22 XP or the top 22 Huion, but xp is very similar and at the best price now) AND an iPad are AMAZING companion tools for short (2-3 hours, imo) sessions and giving variety to your work day. For a hobbyst of the kind of 2 hours sessions (and I don't say it randomly, that number), in the field of illustration, an iPad does imo suffice, tho. IF you are fine with the OS issues, like color calibration flexibility, files (even with the iOS 13, iPadOS  13 improvements -finally can zip/unzip files, yay. Lol. And pencil latency cut by half, that's good- or helper file browsing apps), and mostly certain industry standard apps compatibility and inability to load them on your OS, and tablet hardware limits (ram an Metal limit for canvases of like 1.5 or 2 meters long at required 300dpi (and some people DO require it tho for a painting could be fine 200...under some circumstances... not really for book/other printed stuff targets, tho)...I wouldn't be able in anyway to work on my most key current gig, for example) then.... in that particular situation of those not being a prob (aka hobby use) , is best to skip everything else and get the iPad. I for sure wouldn't get a MS Surface for sketching (strongly dislike the wobble or high stabilizer to get it just right, and palm rejection issues in several apps) but would get an iPad pro instead. For exclusively fast sketches, even an iPad 2018. 
Besides all that... I have compared thoroughly drawing, inking and painting on 12 and 12,9 inches and 22 and + .... there's no point in even comparing doing a complex project in that (both screen and tablet gesture space) or a 22 inches screen and tablet. My Intuos XL is 65 cm wide, and couldn't like it more.... This thing has helped me produce tons of work ver 11 years. Very fast and comfortably.
Long story short: I do believe an iPad is a very nice tool to have once you get first the workhorse solution that have no technical limits in software/pro market apps/OS, tablet size,  ergonomic position (and so allow longer periods of work time without physical issues appearing after some months (or days)) and all. For a 2 hours a day hobbyist with no clients, this surely wouldn't apply. What Scungio has at home is the ideal tool set in every freaking sense, but not every one has that budget  ;). 
 
EDIT:  Wait... you said 1200 pounds. If math and the exchanger thing isn't failing me, this is more than enough to get you both the Wacom L and and XP 22E pro. That's an amazing combo. Or the Wacom L and a Ryzen, lol... 386 pounds for the Wacom L at the Wacom UK store... leaves u with 814 pounds , that's 895 euros. I quite well know that you get a really nice latest 3rd gen Ryzen (if already having your monitor, the usual thing) with quite less than that (500 - 700 euros, mid-high range mainstream). While just the iPad alone, at least first hand from Apple, is 969 pounds in the Uk store. And the 64 gb seems to be too risky. the 256 version is 1119 pounds (1230 euros)... You're still on time to get a Deco 03 (and it's a medium size) from XP-PEN's summer discount with the remaing 87 euros from your total 1200 pounds after getting the ipad. A medium classic tablet for the computer + the iPad ain't a bad deal , either. One that I wouldn't do, ever. But it's another possibility.

I have the large 12.9 inch iPad Pro second gen and the first gen Apple Pencil. I also have the iPad 2018, 9.7 inch model. To me I love it as much or more than the various Wacom products I have had over the years.
The apps have started to come to iOS. You have the Affinity products of course, but also Procreate and Clip Studio Paint. There are those that hate iOS file management, and supposedly there are big things in store for iOS 13 but really, I have been getting along fine with Sratospherix FileBrowser as my Mac OS Finder replacement or iOS. Readdle's Documents is another worthy Finder replacement for iOS.
I am not a big fan of the second gen Apple Pencil. Yes, it appears better in most regards but fails me in customization. With the first one I can use an assortment of custom pencil grips. I have always preferred grips with pens and pencils. I am partial to this UK company named Ego that makes Apple Pencil grips. But now with the double tap functionality of the Apple Pencil 2 how do I do that if I have a pencil grip? How do I charge it with a pencil grip on it?? I am in the minority on this I know but I will really miss my first gen Apple Pencil when I upgrade to a new iPad Pro in a year or two.
It will be interesting for Mac users how Apple's Sidecar works out and develops. Could an iPad Pro be a replacement for a Ciniq? Could Apple make even larger iPad Pros?? Who knows?
It is important I think to not try and shoehorn everything into one device or expect one device to be great at everything. There is a reason why I have a Mac Pro and a Ryzen PC, why I have a laptop and iPads, why I have a Wacom Intuos Pro medium sized tablet and an XP Pen 15.6 Pro. I like to change things up and sometimes things work better in certain situations. Pick the right tool for the job at hand.
For example, say you want to do a pattern, a repeating pattern, have it be a vector. Yeah, some may go into Illustrator to do that, some might even do it in Affinity Designer and use symbols as a workaround to get it done. Me? I first turn to Lost Minds Patternnodes 2. It is this parametric, node based app that gives you so many options and possibilities. You can even do animations with it. Anyway, you could develop this repeating pattern, really complex and then export it out to use in Designer. But this app is only on Mac OS, so I would use the Mac Pro for that. As I have gotten older I have tried to become platform agnostic, and not tie my wagon to any one OS but at the same time I try and take advantage of each OS and what it has to offer.

Just a note on the XP Pen 15.6 Pro, it is currently selling for $320 on eBay by various vendors. $320 is just an incredible price for what you are getting. I am not an XP Pen employee just a really satisfied customer. It is a great time to be an artist and in need of a tablet or display tablet, just so many options and companies to turn to besides Wacom.

thanks for the wealth of information. 

I was really torn this year when buying a new display tablet. Wacom has started to make more affordable Cintiq models by stripping out some features from their pro lines.
I am opposite of SrPx, I prefer smaller displays, wanted something along the lines of a 16 inch display. I like being able to be more portable and take it along with my laptop when the need arises.
So, I look at the Wacom 16, not the Wacom 16 Pro, and really I was not that thrilled with what they were offering. A 1920 x 1080 resolution display with 96% sRGB/72% NTSC, 3-in1 cable setup, it comes with retractable legs to give you, what, 20 degree working angle, and no express keys. You would have to pay extra to get the Wacom Remote to get the express keys.
That would bring the price to $750 (Wacom 16 $650, Wacom Remote $100).
I then looked at the XP Pen 15.6 Pro. It offers the same 1920 x1080 display but has 120% sRGB/88% NTSC coverage, has the same 8192 levels of pressure, comes with a cheap, but functional stand that gives you the same working angle, 19 degrees? It differs from the Wacom 16 in that it has 8 express keys and a Red dial, scroll ring. It comes with the same 3-in-1 cable type of setup. Pen does not have to be charged. The laminated display of this XP Pen 15.6 Pro really does improve parallax greatly and I think eventually they will update their 22 line with laminated displays as well.
The cost of the XP Pen 15.6 pro was $400.
Did I want to spend $750 or $400? No matter which one I chose, I was going to calibrate the display with my SpyderPro. And a better stand would need to be purchased regardless of which one was chosen too. The one clear advantage that Wacom has is the pen and software/drivers. But is that advantage really so great to be worth the extra $350??
In my mind, no, I think XP Pen is close enough with their pens and drivers. Wacom has decades of experience, I think they were founded some 35 years ago? And XP pen was founded in 2005? Yeah, Wacom has way more experience and development time in this field but I do think XP Pen has made a lot of progress lately. I think XP Pen and their drivers are second to Wacom, I think Huion and the other companies are not quite as mature and lacking in their drivers and support. Just my opinion of course.
Anyway, I bought the XP Pen 15.6 Pro and it has been a fabulous experience. My favorite 'feature' is that I don't even have to use all of the 3-in1 cable. I plug in the HDMI connector and one of the USB connectors and the remaining USB connector goes unused. On both my Ryzen PC and my Ryzen laptop, they both provide enough power to run the display. I don't have to use that last USB connector to plug into a wall outlet. So I am able to go out and about and use the 15.6 display with my laptop and not be worried about being tethered to an additional power source, wall outlet, etc.
If I remember right I got something like 220 nits of brightness when measuring the 15.6 Pro, I believe the Wacom 16 is 250 nits? But the color gamut of the Wacom is worse and I think the XP Pen has the better display.
Now if I considered the Wacom 16 Pro, that has the same form factor as the 16 but more of the high end features that you associate with the Pro line. 4K display, etc. But a jump in price to $1,500? But it still doesn't include any express keys and you still would have to buy the Wacom Remote, so the total cost would be $1,600??? And is the display really better in terms of color gamut? Better than the XP Pen 15.6?? And then I have seen really bad reviews of the early buyers of the Cintiq 16 Pro, seems Wacom did have quality control issues with the first year of this model.
So, I ponder to myself, $400 for the XP Pen 15.6 Pro or $1,600 for the Wacom 16 Pro? What could I do with the $1,200 difference between the two?? Well, I could buy an Nvidia 2080 Ti for that much money. With so many programs now using CUDA or OpenCL, using both the CPU and GPU, my time in Blender or Resolve would be much, much nicer with that 2080 Ti card.
I am happy with my choice of the XP Pen, for now, but even if I had the budget of $1,600 say, I would still choose the XP Pen.
One last thing, it was mentioned earlier about taking into account your desk and the space you have. I can't stress this enough, having a quality desk seems to be way down the list of priorities for artists and if anything it should be right at the top. I had an Anthro computer desk and various accessories and it served me well for 20 years but I decided to upgrade to something different this year. It was a do it yourself project. I bought and assembled my own sit/stand desk. I did not go with an electronic motor but one that has a simple, rock solid manual crank. I went to Home Depot and bought a butcher block counter top, 5 foot, 1.5 inches thick put a couple coats of polyurethane on it. Together the frame and desktop weigh about 100 pounds, it goes from 27 inches to as high as 50 inches. So, I can sit in my ergonomic chair and then change it up, crank the table up and stand and work. I have a nice floor mat that I stand on that has various cushioned structures on it so that you can shift your weight, massage the arches of your feet, etc.
With my regular displays mounted on arms, I can push and move them around, and there is just so much space to set up the XP Pen 15.6 Pro, to have my Ryzen laptop on the desk as well, or to have say my iPad Pro set up as well. So often I see Youtube videos where artists are using so little space, I get claustrophobic watching them. It is like a juggler going into a tiny closet and trying to juggle. Yeah, I guess he can adapt and figure out how to do it, but why??

The Cintiq 16 is better calibrated by default than XP-Pen or Huion, but anyway, I'm of the ones that believe that you need to hardware calibrate all your screens, no matter what.
You ask/mention this to the wrong guy ... As I hate with a passion to paint in a screen as small as 16 inches. A 22 inches one is much better. That said, again, it depends. I've been painting for decades with classic tablets of all sizes, but was 8 months with a cintiq, doing my usual work.... I don't recommend it for the full-day-grunt (hello!) kind of illustrator. For a part-time thing, yes, even more for a 2 hours per day hobby, yep, too. Drawing over a screen, due to the distance to the eyes, position of back and neck (even with an ergotron), and other things... I prefer classic tablets if one is going to put 8 to 10 hours a day. But definitely, I wouldn't buy a 16 inches screen-tablet. The surface area for drawing is almost fine, but not the screen size. And the one thing shared with the 22 is that I think is less ergonomic than a classic, with your monitor vertical,  at the right distance and all, back and neck straight and its muscles/tendons 100% relaxed (some people need to train this, though, it's a mindset, but is trainable by everyone) all those hours,  specially many hours a day, all days of the week, during years. So, since some time I 've become a great defender of the classic tablets. Also, this allows one to focus in a great professional monitor, as a separated thing from the drawing tablet. And these tablets actually quite cheaper, too, while providing the same or more pressure sensitivity levels, etc.  XP-PEN has quite cheaper models for the 22, also. That's normally, but now in the summer offer time, it's crazy, I believe it's even cheaper then a cintiq 16, (or any other 16 from any brand, till 15th September) by quite some difference... lemme check... yeah... I mean... c'mon.... 400 US $. LOL. And yep, is not "well" color calibrated (no screen is, in purity) by default like Wacom Cintiqs, but anyway, anyone just minimally serious, doing this for paid work, needs to calibrate the monitor by a hardware calibrator (be it a monitor or a display-tablet), and there are some dirty cheap in amazon. And if one doesn't have one... bad thing... is a must.. and one can use it for all the monitors in the studio or home. This is a must for whatever the brand, XP, Huion, and personally, I don't even trust Wacom fully for that. I'd calibrate a Cintiq...
I mean, TOTALLY keep recommending you and whoever (not really, a stupidly rich individual is better off with a Wacom L and Cintiq 32 combo) the Wacom L over anything, but if you really feel (but study well the case...) you need to draw over a screen - don't get me wrong: I think saves time and all... I'd just have it as a companion, to cover some hours a day, or some stage on each project-  do yourself a favor and get this 22E Pro. And I know...it's rechargeable pen, non battery-free, while I have been pestering about that just some posts above... but tends to happen in alternative brands at this size, dunno why at 16 they have all that ironed already (battery-free pens and other advances appear first in the 16" models). But that's how much important I think the screen size is, to work seriously even just during 4 hours. The 22E Pro model from XP-PEN gives u 2 rechargeable pens (so u can keep drawing with one while charging the other), if I recall well, and if notice some jitter/wobble, besides is compensated with a greater accuracy due to having a much larger active area, -more control over the lines- well, do the dirty trick, activate software line stabilization (use the lower values possible). Affinity photo supports it (and anyway, in AP you need it when drawing zoomed out). It's a no-way in a classic tablet, as at least you don't have to care about other issues as in display-tablets, so, one shouldn't admit today a classic with rechargeable pen, but I mean, it's a trade in the end. IMO is preferable to get a 22 inches screen with rechargeable pens for painting, drawing and inking, than a 16 with a battery-free pen, by far. 
I insist... I prefer the Wacom L, as your main work horse... Then, later on with a nice gig and money in the bank, the cintiq-like, as you could use it for portions of time in each day. My 2c.
The 22 model (400$) ...btw, don't get the "non-E"  ... that other one as no function keys, and quite worse cable management, can be a problem :
https://www.storexppen.com/buy/artist-22epro.html
In Amazon UK, as I believe you mentioned prices in pounds, hardware color calibrators at good price (I can only speak about i1 Display Pro, which is the one I have and use, and works great, but some of these below are said to do fine ) :
My super loved one, i1 Display Pro, still rocking after a bunch of years :
https://www.amazon.co.uk/X-Rite-i1Display-Pro-Professional-calibration/dp/B0055MBQOW/
Then the others   
https://www.amazon.co.uk/Datacolor-SpyderX-Pro-Calibration-photographers/dp/B07M6KPJ9K/
https://www.amazon.co.uk/dp/B00UBSL2TO
https://www.amazon.co.uk/X-Rite-ColorMunki-Display-Calibrator-Projectors/dp/B0055MBQOM/
I mean, no matter if it's 16, 22 , a Wacom Cintiq of the cheaper line, or Huion or XP-Pen, or a classic but one does not have yet a calibrator, IMO, it's a must. If already have one, then, is less investment now...
EDIT: About the tablet, at Amazon Uk there's no discount, it seems XP-Pen offers that to get more ppl buying directly from them... but if you have to buy all from Amazon for security or sth, it's quite more expensive there, and yet a stupidly good bargain (a steal) :
https://www.amazon.co.uk/XP-Pen-Artist22E-Interactive-Shortcut-Adjustable/dp/B01M28DHOA/
Great offers. But I still keep recommending the Wacom L over any of these. Now, I recon some people don't want to spend the time training the eye-hand-screen coordination thing with a classic tablet. I mean, I can understand that. But is .. acquiring an extremely valuable skill. If one ends up at company, is easy to transition to a Cintiq, but quite hard doing the opposite, from cintiq to a classic if never used the latter, in the intensity of a new job and all. Also, if you get the tablet broken out of warranty (happens to many) , and you are used to classic tablets, is WAY easier on the pocket to get a 100 bucks Deco 03 or Huion to solve the day than needing to improvise a large investment in the middle of the month, to end gigs or etc. Is a more sustainable thing, so to speak.

The one I am looking at is the Series Intuos PRO Large PTH-860-N, but for a similar price point there is also the XP-Pen Artist16 Pro 15.6 Inch Drawing Tablet Graphics Pen Display FHD IPS Monitor 8192 Pen Pressure with Shortcut Keys & Adjustable Multi-angle Stand, which from readers reviews and Q&A indicates people are using it with Affinity products.
Though I think XP-Pen Artist16 Pro is penned against the Wacom Cintiq 16 
 
Choices, choices, choices.

Then... go Wacom L.  You wont regret it.... Best of the best.  I kind of wouldn't particularly go for the Paper option (slightly more expensive), unless you are very curious about the matter, or are a comic inker, and trust on your own tricks to overcome certain issues with that Paper thing (one of them: it's gotta be with Wacom's ink, not a regular cheap ink cartridge. Same story than, hey, why are printers so cheap... 'cause the business is in the ink.... ).

Wacom L is IMO all one needs as a professional, top of the top . I am using an XL since almost 11 years.
Now, if want to save money, I agree with the above poster: The Deco models from XP-PEN are very cheap and yet very, very good and reported to work well with Affinity (specially the Deco 03, more instances on that one).
My recommendations (other than the Wacom L being my all times favorite, and this including the display-tablets, that is, weird for many, but I prefer the Wacom L to a Cintiq) are the Deco 03, the Deco Pro MEDIUM (BEWARE, THERE'S A SMALL MODEL),   and the Deco 01 V2.
The Deco 03 -> because a lot of reviewers talk wonders about it, as well as several well known users here, and some friends of mine (also pros in illustration and/or comic) unrelated to this forum. 80 dollars.(now. Normally is 100)
The Deco 01 V2 (be VERY sure is V2!! Not just Deco 01 !!! -> For no particular reason other than the price/what you get (active area size, 5080 LPI, tilt!, 8k pressure levels, battery free pen, on board buttons... for 48 bucks, I mean, u kiddin' me???) ratio is amazing. Sadly, I have not even checked reviews about it, yet. It has some features not present in the other two, in part as is more modern. 48$, but dunno what's the usual price.
The Deco Pro (MEDIUM) -> Well, if the Decos seem to be quite compatible with Affinity, why not this one. Several well known youtube reviewers are in love with this one. The wheel has double function, so, can set there for example brush size and zoom, and overall, seems really the pro part of the name is justified. Now seems you can get it (didn't know they have these summer discounts) for 100 bucks. A steal of a bargain.  Normally ain't expensive, tho, around 130.
it's 10x6 or the like for all the models, although the Deco Pro Medium is bigger, 11x6 (careful, in the store's product comes pre assigned to the 9 inches one. BE SURE to click on the 11x6 option). All these are significantly bigger in active area than Wacom Medium. And this is rather important for line stability and control in general.
Still, my preference goes with the Wacom L. But I would be pretty comfortable working with any of these 3. Also, they're all battery free pens with lots of pressure levels. I like the idea of having sustainable hardware and software. (ie, cheaper to replace if it breaks, while if one only is willing to work with a cintiq 32, it breaks out of warranty, there's a huge problem if it happens in the middle of a month with not much in the bank, while a perfectly capable 100 bucks tablet would save the day, if you got used/trained with it. The same I say this, I strongly recommend not going for a small tablet if willing to draw and paint (for other tasks small ones are good). Is possible to work with small ones, but if 100 bucks is not something crazy for you, it has a great ratio of cost/quality, in these 3 products.

Not sure if the type-c of the Pro model is better fit than what the others bring. As I don't use anything Apple.
https://www.xp-pen.com/product/432.html
It speaks about it, scroll to the middle.
The Deco Pro is the first drawing tablet that comes equipped with a Type-C port. Now you can directly connect your iMac/Mac Book Pro and other Windows computers that support Type-C input to the Deco Pro without using a Type-C to USB adapter. Its interface is symmetrical, making it equally comfortable for right- and left-handed users. You can also rotate the Deco Pro to 0 degree, 90 degree, 180 degree and 270 degree depending on your different creative requirements.