I would go with something like this
http://www.reefcentral.com/forums/sh...hreadid=354940
I have a corner one on my tank and if I could do it again I would go with one in the center. You would be able to hide it with aquascaping plus I find the corner one to be noisy no matter what I do. I think that if the overflow is surounded by water on 3 side it would help as an sound insulator