The Remora Pro is a HOB but it can HOB of a sump if tall enough. That's the only issue, otherwise it will only be more efficient at skimming since the water in the sump is skimmed from the surface where most of the DOC resides anyways.
If you haven't figured it out yet I like to BOLD links :P
Well I just measured the skimmer with the cup and under the tank for clearance and not enough room to put a sump there and teh only other place I would have is to the side of the main tank, which then would be infront of a window but kinda afraid of putting there even though I have heavy curtians over the windows. and cant put it on the one side of the tank since I have a vent there. Any other suggestions?