off the self fuel tanks?

[mada]

My fuel tank was located underneath the console, and I'm planning to move a new one under the deck. I only have approx 24 1/2" between the stringers and a depth of 9 5/8 til' the bottom of the center stringer.

Does anyone know if there is a off the shelf tank that will work in this situation? I need anywhere from 30 - 50 gallon capacity.

Thanks!

[mada]

That should read off the shelf?