I've unashamadely stolen Chimera's tank design - an Oceans motion 4 way wave maker with 2 outflows into a single pipe into the OM, then one under coral return, and 3 returns in the top of the tank.
I've planned a dry chamber in the main body of the tank to run the piping from the cabinet below to the hood level for the retuns. I didnt want the tank to be out from the wall to cater for the return piping, so this seemed like a good solution.
Hope that makes sense, if not I'll pull some more plans out of CAD and see if pictures do a better job of explaining!!!