aleok's 112 gallon build

Hi folks,
I'm in the process of setting up my 112 gallon tank. the tank was used previously as an African cichlid tank but I've decided to go saltwater!

Here's some pics of what i've done so far:
the tank has a built in overflow on one side

As far as my sump setup i'm still fishing for ideas... The Red Arrow is where the DT will drain into the sump and the Blue Star is where my pump will be placed (non-submersible).

The small tank represents a 10 gallon I want to use along with the 20 gal long. I wanted use the 10 as a refugium. anyone can give me some ideas on how to set up my stuff down there given what i got? thanks!