The tank doesn't have a sump, I'm running a canister filter underneath it in kitchen cupboard. I made a small overflow for it where I have the pump suction. It needs manual adjustment every few days to ensure the water from the surface is being sucked down. It seems to be working out ok.
If you go to
www.walltanks.com you can see what I bought. I was a little off on the dimensions, it is 16" high and 6" wide.