[Myka]

You will hate life if your sump is 22" deep and inside a stand. Depending which skimmer you use, that means the top of the skimmer would be almost level with the top of the sump.

I would really try to modify your stand design to accommodate a sump 18" wide. Are you using 2x4s? I can mock up a design for you, or find a pic online. The trouble with bottom drilled tanks is that there isn't room at the back of the tank to run a 2x4 because the bulkheads will be in the way. That's why I went with a steel stand for my tank. The steel is 1" rather than 1.5" with a 2x4 which is the difference between it fitting and not fitting. Do you want your stand to be flush with the tank and thus be 40 x 22" or do you want the stand to be a bit bigger than the actual tank? If the stand can be 41 x 23" then you'll have room behind the bulkheads to run a 2x4 on edge. How tall do you want your stand?