Thanks Jeff! I'm going with 24VDC, just ordered it!
I found awesome news! People I'm talking with say that a 1-2 ton oil separator will work just fine on this build. So I ordered this beauty!
Q E HVAC R Refrigeration Oil Separator 1 2" ODS New | eBay
Parts come in! First off is 20 on 316 stainless steel for the coil in the fish tank and 2 sizes of cap tube. (Might not need them for this build, but just wanted to be sure.)
Next is 5x SUD115 and 45% silver braze
And finally the 2 Inkbird Thermostat/relays
This build is going to have all the bells and whistles because I need to be able to really test it out to see if the 4 ton build will work as planned.