Keep in mind the 3600x stock is already 3.8ghz but should boost up to 4.4ghz. Not sure how much overclock you'll be able to get.
I'm running a 1700x on a b350 motherboard at 3.8ghz overclock. Which for many of those, 4ghz was considered high.
Depending on what budget you've got, you might consider just picking up a decent b450 board. Just be sure it supports that cpu out of the box. If you are really cheap, you could get the 3600 and a little better cooler and overclock that.
But I would say if you're on a budget, get a mid range board and use the money saved towards an upgraded graphics card.
Depends on the features you want...extra M.2 slots, PCI-E 4 support, high end cpu support. I would recommend staying away from the Gaming X as the vrm is on the weak side for an x570 board. The chart below lists the boards by suitability for highend cpus if those are in your future plans.