You should probably go with AMD, if you want bigger upgrade go for Ryzen 7 if you want to go with smaller upgrade Ryzen 5 from 3000 series. Based on current games 8 cores is maximum used by games, after that you don't see difference in many games (FPS stays the same). So Ryzen 7 3700X should be your best bet. Now with MB is bit different. Newer x570 still have some issues that will be ironed out and they have PCI Express 4.0, but x470 are more stable and refined at this point but without PCI Express 4.0. And if you go with AMD get fastest RAM you can at reasonable price, that is basically what matters the most for RAM.