pickups at each long end with the outlet in the center and the main filtration benith. I figure 2 .... 1 1/2 HP pool pumps and a series of pressurized cannister filters...(sea clear, tru view...ect...) feeding a centralized 24" bio-tower.
This would be a awesome tank if you were to build it i would use acrylic to keep weight down and also it would be better for the cuts on the middle piece
I did a little drawing of it on sketch up i made the arcylic thicknes 1/2" but might want to go a little thicker not 100% sure on that one
I drew it with the width at 2' and the depth at 40" like in your drawing