So parts arrived.
I decided to just use the cooler that came with the 3700X and make sure the bios updated to support 3rd Gen and to install windows fresh on the 970 Evo Plus.
Once done I disconnected everything and when trying to remove the cooler it seemed really stuck (was original thermal paste that comes pre-appied on cooler). I remember hearing about this from YouTube videos and online forums so twisted it a bit to try pry it loose and the whole CPU popped out still stuck to the cooler (with retention arm still down

). The thermal paste was also everywhere!!! It was only on for about 30 minutes total. So had to clean every part of CPU. Luckily CPU fitted perfectly back into socket and retention arm locked it in place.
Tomorrow the "fun" starts when I get to start planning and bending the hard line for the water-cooling.