[Myka]

Personally, peninsula tanks are my favourite, and because of the flow challenges I would be considering a closed loop or two rather than powerheads.

Are you planning a canopy or open top?

I would not ruin the clean, open look of a peninsula tank by putting a central overflow in the tank. Corals have a tendency to get "windswept" looking in peninsula tanks with the overflow on one end though because it tends to get a gyre flow - especially when you're trying to get any surface scum to come back to the overflow. Peninsula tanks always look best with no powerheads on the glass, and only positioned on the overflow end, but this makes random flow even tougher. This is why I would suggest the closed loop.