Lighthing a cube with center overflow

[summer6]

Anyone have a large cube ( 4' to 6' and about 24" depth) with a center overflow?
If so, would you please tell me how the lights are situated in relation to the overflow?
Do you have to worry more about algae growing in the overflows when it's centered in the tank?
I'm thinking about an open aquarium and would want to use pendants with halides/T5's.
My guess would be put two fixtures running parallel to eachother - but not sure if this is best.