I’m not suggesting Intel (though it looks juicy) because they have a super confusing set of sockets in the market right now and none are compatible with even each other, forget backward and forward compatibility. Go for the AMD rig already suggested.
As for PSUs, there’s Cooler Master’s Real Power series, Tagan, Antec etc that make high-end PSUs for gaming rigs. Research their sites to find out the model numbers. They also have modular power supplies. Some prefer that and some do not. Choose according to your preference.