@Gargron Gotta second the pcpartpicker.com recommendations. I hadn't built a PC in decades, but they helped me put together a decent mid-tier gaming rig.

I saved about 30% on the price of a pre-built, and they ensure all the parts you get are compatible. Had it up and running in just one day, with minimal instructions. The result is performant.

There's also a lot to be said for sticking with current hardware as long as you can, though. Moore's Law is dead.