Hey Chris,
What type of corals do you want to keep? Becase it seems like most people want to end up keeping SPS so flow and tank turnover are high on the list of prioritie when setting up a SPS tank. My opinion is to get holes in your tank that can hold lots of flow, like Mike said, two 1.5" bulkheads in each corner should be nice.
Make your own overflows out of black 1/4" acrylic. You can either make them a 90° box in each corner or some people choose one piece 45° overflow box's. You also have to figure out what size the "teeth" should be depending on how much flow you want.
Also, for tank turnover and flow a return pump is a good source for this. LG 4MD, Mag 18, Mak 4... it doesn't really matter. Even smaller is ok as long as in-tank circulation is good.
HTH
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