The problem right now is Graphics Cards (GPUs) are incredibly scarce to find, as the new models have launched in the last 4-5 months. Even older models are non-existent stock everywhere you look, and if they are in stock they're stupidly over-priced. The same situation is happening with the new PS5 and Xbox models...
The pre-built PCs on OcUK aren't that great on particular parts imo. If you need it pre-built, my suggestion would be to post in OcUK's
customer service forum here - give them something like the below custom part list... and ask what "build stock" gpus they have available if any!?
at the same time ask how much they'd charge total to build this system up for you with the graphics card. something like a nvidia 1660 super, 2060 or amd 5600 xt could be possible... (i noticed they have msi 1660s in build stock on their configurator)
the below would be a great system (with a decent gpu added). not sure why he wants "200 fps" sounds like he's heard his friends talk big numbers, it's not needed lol. a 1660 super would give him 100+ avg fps (@ 1080p) which is more than enough. but if you can somehow manage one of the new models like a 3060 ti then you'd be laughing for £370.
edit: you would need to buy windows 10 which can be had for £5-10 if you look online at auction sites etc.
my basket at overclockers uk: