There are a few questions you need to answer that impact the specs.
What resolution will you be using for your monitor, 1080p or 2k or 4k. If you are 1080p gaming then you really do not need the latest and greatest.
Do you want to pay extra for a "future proofed" machine. I think buying future proof is a meme the stuff lasts so long especially on linux.
Do you want to pay extra for a smaller case and smaller parts.
What games do you want to play? Sim games require a decent CPU everything else you can get away with the lowest end CPU and its fine. 5500 5600 and 5600x are solid value AM4 cpus. If you have money for future proofing you can look at am5 CPUs.
For gpu ifyou are 2k or 4k gaming 9070XT is the best value card on the market right now.
For 1080p the 3060 or 3060it is a solid card at a solid price. Dont worry about nvidia compat its fine. It takes a single line pasted into the terminal to get the drivers and most distros have a GUI tool to get them if you dont want to do that.
As for distro it really doesnt matter, they all use mostly the same tools and software. Bazzite, fedora, Ubuntu are good places to start. If you want a "gaming" OS, cachyOS, nobara, pika have been optimised.
For specs that are important, if you need WiFi its nice to get a motherboard that has WiFi on it. Nvme ssd drive 1tb or 2tb is really nice.
Consider picking parts and building it yourself you will learn about how it goes together and fixing it will be much easier. You'll also have a lot more freedom for customisation and part pricing. I had a friend who is not technical at all build a PC and he said it was quite easy he just followed a video from linus tech tips. Took a few hours.
This got me so excited because i thought the game was being remastered or reignited. I'm happy they are making steamdeck based improvements because its a great steamdeck mmo. But most of the stuff I already had through gwtoolbox so i appreciate the gesture of support.