In terms for motherboard - i would go with MSI brand, they have very neat, 2 buttons that do light over clock for you. All you do is press button (its in bios) and reboot, check stability and if it works you are all good. No need to know all backend tricks with clocks, voltages or timings. For example <200$ x570 MPG GAMING PLUS is not expensive and performs good. The good memory is a must. You can even use standard 2133 or 2400 (SPD) "green" sticks and you will get 13khs on 3900x. I tried it with stock wraith cooler and i think its a bit small for everclocking as cpu gets to 80'c range...you can get COOLER MASTER like this https://www.newegg.com/cooler-master-hyper-212-evo-rr-212e-20pk-r2/p/N82E16835103099 its 35$ and works better then original wraith cooler. Just add rpm's or second fan and you are good to go. But anything like NOCTUA or equal or watercooler with 3 fans (360mm) will be the best.