Eshoops makes a great continuous siphon overflow with a prefilter box ($65). You wouldn't have to drill your display or fuge. Mag drive 7 return pump would work to return the water to the display ($70)
i am researching the same thing. have a 55g i want to make a frag tank but it isnt drilled and I want a fuge. an HOB overflow is the way to go. then just hook up some PVC to the return pump all the way back up to the tank for the return.
