Hypothetical reef tank

[michika]

I'm debating tearing down my 24g nano for a longer, and shorter tank. I want to get some feedback in regards to flow, and what options I may have with a smaller system.

The system I am thinking of creating would be approximately 3ft in length, 18" in depth, and 15" tall, but I would restrict the water height to 1ft. This would put the display at about 42g before the overflows are in.

I would like dual overflows, and possibly 4 returns. My goal is to get as much flow as possible through the system.

What would you recommend I do, or use to create a variety of random currents throughout the tank. The tank, as mine is now, would be SPS and clam dominated.