Case is easily the longest time usable part of PC.
(mine going toward 11 year age and at this rate will be used for long long time with fashion destroying case designs)
So better to avoid bigger skimping on it.
Meaning what kind of case your friend would like?
Like would he like case to muffle components noises some?
Cheese grater cases leak all noise out unmuffled.
Next-gen consoles are going to bring huge jump to CPU power requirements of multiplatter games.
So for CPU AMD platform is better with proper upgrade path.
12 cores/24 threads is likely £300 level already at summer and next year likely sees another round of updated processors for AM4.
Though while having decent good strength VRM that particular motherboard has old fashioned lower efficiency VRM design.
There's very little reason for going for waterpipe coolers.
They're basically lots of fashion hype.
For actually better cooling performance than in heatpipe coolers you need to go for really big radiators. (of expensive custom loops)
Otherwise all you get is lot more things which wear and can go wrong.
With pump being extra noise source.
For example Mugen 5 would be just step below top performing heatpipe coolers and like
https://www.overclockers.co.uk/scythe-scmg-5100-mugen-5-cpu-cooler-hs-046-sy.html
Here you can find both it and that Corsair H100i, which gets beaten in cooling per noise:
https://www.tweaktown.com/reviews/8857/corsair-h100i-pro-rgb-liquid-cpu-cooler-review/index6.html
Again that expensive NVMe drive is something which gives very little real world benefit for extra price.
Only really noticeable speed difference to SATA SSD would be in copying big files back and forth.
Neither I/O or transfer rate is real bottleneck in basically any other thing normal user does.
https://www.techpowerup.com/reviews/Crucial/MX500_M.2_1_TB/8.html
https://www.techpowerup.com/reviews/Crucial/MX500_M.2_1_TB/13.html
In SATA-signaled SSD you can get that 1TB for £130
https://www.overclockers.co.uk/crucial-mx500-1.0tb-2.5-6gbps-7mm-solid-state-drive-hd-06g-cr.html