[sphelps]

If you build an actual external overflow on the back of the edge and notch the acrylic on the back basically all the way down it should be able to handle the flow but to get the edge effect the water level has to be above the glass top which limits you to a very small surface area so you don't have much tolerance so using a fine mesh screen is probably not a good idea making it difficult to keep smaller fish or shrimp. For that flow rate a 1/2" return and a 3/4" drain will be sufficient.

Like I mentioned before though I think you're heading down the hardcore overkill road but it's up to you. My LPS and soft corals do great with only 50-60gph. SPS have their place but I've never seen a pico tank with SPS look as good as one with LPS and soft corals. Often we get the idea that the uncommon is cool and impressive however sometimes the more common approach results in a more impressive tank.