Warning, I’ve had an issue in the past where I couldn’t play a game (Deus Ex Mankind divided) because it needed a specific instruction set on the CPU (SSSE3). While not your specific case since the FX-8350 supports SSSE3 (I should know, that was the exact CPU I switched to to be able to play the game) there might be newer instructions sets that this old CPU does not support.

Also that GPU is older than what people like to remember, from a time where AMD was the worst GPU option on Linux. It’s very likely that the open source driver is good enough for that card by now, but there’s a good chance you might need to wrestle with the AMD proprietary GPU driver (fglrx) which is worse than the Nvidia one in some aspects and some distros don’t even package it anymore.

If you plug your Nvidia GPU that rig would be usable for gaming, I’m not sure what fps you would get as games keep getting updates and old hardware remains the same so old benchmarks might not be reliable, but I suppose it should run plenty of stuff.