I disagree...nothing wrong with the nitro+..the psu you've chosen even has the 12x4 connection for it. the gpu isnt a 5090 drawing 600w of power, the the connection is going to be fine, it's not going to melt jack, and that card is well built, premium finish and fast..and silent too. the hidden cable system is pretty awesome.
if you're going to spend £190 on a 1000w psu, might as well get the 1200w for £20 more..at least you can upgrade to a 5090 down the line or whatever is out at the time that has that king of power..600w draw, plus cpu and everything, you'll be running it 50-70%. rather than 80-90% (esp if down the line you upgrade your cpu also to something that might drink some more)...otherwise just ask whoevers building it for you for a decent psu with 10yrs warranty..
actually just had a look and the antec 1000w is £170 elsewhere so check price with your system builder..£190 too much. Asus tuf 1000w been a good seller, not too expensive..msi mpg a1000G also good..standard price£10 but ofter goes to £140(dfon't pay more)
nzxt c1200 gold can be had for £160 and is highly recommended by TPU..the 100w version is £144

we're back to the 32/64gb debate...
my view
32gb is more than enough for games he's listed. new games take years to develop and unless he's going to play heavily modded games such as DCS it's just wasted. Even new games coming out now aren't using anywhere close to 32gb in games
this guy own cataclysm games..guess he sells enough pc's not to want lots of returns..makes it nice and easy
hogwarts used 22gb that was highest hu got
that being said, £140 for 32gb is a lot for 6000c28 when 6000c30 can be had for under £100..stump up to £185 for 64 6000c30 if you have loads of chrome tabs and maybe your work is ram heavy...general pc stuff doesn't count there i think...but from what op said, think 32 is fine
@Tetras hope I'm not comiong across forcefull here...I enjoy our discussion on ram and genuinely not trying to just dismiss your view...i just havewn't found a game that comes close
now i've got my 'nitro+'

, going to load cyberpunk again at high setting with rt and see ram useage..got hogwarts too so will see that seeing as theat was a heavy use case for HU