The PSU is the issue and needs to go.
www.jonnyguru.com
While this is the 600W unit and not the 700W like you picked out, from what I've read Enhance makes all of these PSUs so they should behave the same. JG has two issues with this PSU, though I'm mostly concerned with one of them. The cross load tests are bad. Horrible really. At a zero load on 3.3 and 5V rail and everything on the 12V rail, 5v and 12v go horribly out of spec. I normally wouldn't be so concerned about this as there is nearly always a load of some sort on the minor rails as drives and what not need them. But what is bad is that it took a load of 2A on the 5V rail to bring things back in spec. That's bad. You would probably need twice that to bring things back to normal, and I'd bet it's very possible to make a build where that isn't possible.
Then you have the scope shots. Not only are the voltage below where they should be, even in non CL conditions the 5V rail can have such a large ripple it's out of spec. In short this PSU is garbage and shouldn't be used. You need to find a PSU that stays in spec, and doesn't have such a high ripple. Your GPU doesn't need 550W all for itself. That's a system with a 2060 needs a 550W. But I wouldn't get the one you picked.
Otherwise things looked good. I'm not sure about that SSD, and the ram is fine. Sure there is faster but you aren't going to double your frame rates by moving from 3200MHz to 3600 or 4000MHz. It's standard stuff, but it will work fine. Just find a better PSU and double check that SSD.