I've been asked to build a custom aquarium stand for a 90 gallon tank. The weight of the water and gravel will be around 1000lbs. Attached is a SketchUp drawing of my design. he would like a short edge against the wall so it acts as a room divider, with a tall cabinet that he can store a ladder and run hoses and wires through.

Most of the DIY builds I've seen are ugly 2x4 construction and the nicer cabinets rarely seem to have any pictures of the joinery or inner construction. I'm curious if anyone has experience building aquarium stands essentially as plywood cabinets and what joinery and structural reinforcements you would use to support a tank this size.

I'd prefer not to use material as bulky as 2x4 because of how much interior space would be lost. Despite seeing stands that appears to be little more than a plywood cabinet, I'm nervous about putting that in someone's home with my name on it. 

I've also looked for some calculators for load/strength with different materials types and thicknesses but haven't found a definitive answer around this. 

Thanks in advance for any suggestions.

-Dexter