MORE PROGRESS!
Plumbing is done! Tank is filled! System is running!
Well, for small periods at a time while testing.
My Reeflo Barracuda return pump is mega powerful. Running only the tank, the output valve is closed down to probably 25% at the most. Once I get the chiller plumbed in, that will let me open it to around 50%. And then once I start up the reactors, that will use up a little more. But I still may need to downgrade the pump. But the sump is plumbed for 1.5" out to the pump so I need a pump with 1.5" inlet. I was looking at some of the smaller Reeflo pumps but they have a 2" inlet.
Anyhoo... still lots of work to do but here's some pics of how it looks now!