Mainly plinking, full power. Had a look at Hw44. Very nice, but rather expensive.
The HW44 is IMO very expensive pistol at £700 or so. I'm sure it is most excellent, am a staunch Weihrauch fan, but it wouldn't be my first choice, even if I had the money for one.
As to calibre, I see absolutely no point in having a .22 pistols with the UK 6fpe limit. Except for some very specialised purpose e.g. ultra close range pest control (controversial). The .177 shoots flatter, faster, further and more accurately. And the pellets cost a lot less.
Possibly consider instead a Reximex Mito. for about £400 Looks rather nice to me.
https://solware.co.uk/reximex-mito-pistol-synthetic-with-stock?search=reximex mito
Or, and still looking good the Diana Bandit, (or one of the other identical things), under £170.
The downside to having a PCP pistol is that you need to carry around some charging kit as well. Also consider that you might find pistols are not for you after all.
So an affordable CO2 full power pistol might suit. e.g. the Diana Chaser (or similar) for about £100.
I too like to muck about with pistols, but am cr@p at it. Still doesn't stop me enjoying it though.
Well, these are my random thoughts. Now I will as usual digress, self indulgently, you need read no further.
Here's what I currently have, in no particular order:
Gamo Compact over lever single stroke pneumatic. Anatomical wooden target grips. Mine is left handed. Capable of high precision. about 3 PE, good for 10m, and shooting indoors. .177 Very expensive nowadays, for what they are, but still the entry level for match pistol shooting.
Two, yes two, Diana/Original model 6G totally recoil-less spring pistols. Why two, well I picked them up many years ago for an absolute song, sold as seen, failed seals, might as well buy the two if only to have some spares. Less than £100 for both, one of them was even new old stock that had been hanging around for years, yet failed immediately I tried it out, first time it had been out of the box. The other one was an immaculate trade-in but either the shop hadn't checked it out, or it too had failed with age. The shop just wanted rid.
As it turned out both were perfect, other than the failed piston seals. All did that with the original seals, but fortunately the factory changed the material and the replacements are pretty much everlasting. I have a (retired but still does work for friends) gunsmith who knows the Giss system (not a job for tinkerers) and fitted the upgraded genuine seals for the cost of the parts. I took a chance which paid off. Nowadays they sell for £300 or so. Very collectable, for good reason. Using the Giss system of opposed pistons geared together. Beautiful. Totally "dead" to shoot. Again .177 about 3 fpe, good for 10m work. Immaculate, with walnut adjustable RH target grips, also I sourced some LH plastic grips (I am a lefty). I call these my duelling pistols and have had a lot of fun challenging others to my own idea of modern duelling (only paper or tin cans etc. involved). Stand side by side facing away from targets. On the mark walk forward ten paces, turn around and five seconds to take the shot. Rinse, repeat however many times agreed. Loser pays for something, beer, lunch whatever. Right handers get to use the anatomical walnut target grips. I have to get by with the plastic left handed ones, so am at a disadvantage.
Webley Tempest, .177 immaculate, original box, from a friend who wanted to give it to me, I said I must pay for it, so £50, he would not accept any more than that. So collectable nowadays I worry about devaluing it. It is so much fun for a little pocket pistol. My original one vanished somewhere about the time I went to UNI. so I was very pleased to replace it much later. Great fun for plinking, and just the nostalgia. The HW45 is the spiritual successor to the the Webley pistols, believe it or not.
Hopefully soon a Weihrauch HW45 Black Star, .177, if I can seal the part-ex. deal.
Once had a Brocock Atomic PCP in .177 but didn't get on with it. Basically I like my pistols to be self contained, no charging kit required, and utterly reliable. Something you can put away for months or years, then come back to and expect it to be working just the same as when you stored it.
The Brocock was not, back to the factory three times for warranty work until I insisted on a refund. Eventually had to get my credit card people to do that for me, Brocock were utterly useless at the time, and went bust shortly afterwards. Then a sorry saga of a brief period with BSA, followed by coming under the Daystate umbrella where they are now.
About Brocock | Quality, Lightweight Hunting Air Rifles Still wouldn't buy a new (very expensive) one though, having been burned, but that's just me.
Frankly any PCP will eventually need at least some o-ring replacements, which is maybe OK if you are a DIYer, can still get the parts, and find some stripdown guidance somehow. Otherwise its a gunsmith job, even if you can find one who knows your pistol. Lack of use is the worst thing for PCPs, they need to be exercised regularly to keep the seals in good condition.