You can do a light OC but remind oversized unit can easily power undersized system, but not the other way around, so it’s best to aim high and overshoot. Oversize power supplies can also be useful down the road if you plan to upgrade your system, as they can avoid the need to purchase a newer, larger unit. I suggest you to buy a shitty low cost PSU for now (or stay with your old one) and change later For a Tier 1PSU.
I see that you have chosen a nice case with a glass. You will need a modular power supply if you want it does not look like a mess inside.
And remember for the motherboard, X370 = AMD / Z370 = Intel