If you do multithreaded or multitasking 5900X is bang per buck choise and has enough cores to handle heaviest games for years with stuff like web browsers etc on background.I was convinved to change to a ryzen 5900X. But the GPU bundle only has intel cards in stock.
Though for gaming alone without nothing on background it's in general somewhat overkill.
For cooler £43 Alpenfohn Brocken 3 would be very good and with flat base guaranteed to fit CPU, if you can fit it into case.
https://www.overclockers.co.uk/alpenfohn-brocken-3-cpu-cooler-140mm-hs-05a-al.html
Basing on picture here it's possible to lower fan to level of heatsink itself when installed:
https://basic-tutorials.com/alpenfohn-brocken-3-black-edition-massive-tower-cooler-with-two-fans/3/
https://basic-tutorials.com/wp-content/uploads/2019/11/Alpenföhn-Brocken-3-24.jpg
Starting from same price level Scythe Mugen 5 is actually slightly heavier for its smalle dimensions with denser fin stack.
https://www.overclockers.co.uk/search?ssearch=mugen+5
but intel optimized convex base kinda relies on deforming amd's convex heatspreader to get good contact at wider area.
direct contact heatpipe coolers again have automatically flat base because of manufacturing process.
for motherboard around £150 level b550 board would work well, if you don't have any special needs in there.
or even £140 if wifi isn't needed and there's no need for lots of usbs.
2x8gb 3600mhz kit costs £75
https://www.overclockers.co.uk/cruc...00c16-3600mhz-dual-channel-kit-my-20q-cr.html
(32GB prices start from £150)
That WD Blue SN550 is £90.
https://www.overclockers.co.uk/wd-b...-solid-state-drive-wds100t2b0c-hd-56l-wd.html
Phanteks AMP 750W would be good 10 year warranty PSU for most graphics card for less than £90.
https://www.overclockers.co.uk/phanteks-amp-750w-80-plus-gold-modular-power-supply-ca-09r-pt.html