1) can I use 10mm glass on the tanks I want to build, given everything I have read the height is the important factor and this "should work".
2) Has anyone set up a duel tank stand with tanks this large before?
1. Yes, I actually come up with 9mm being needed, so 10mm should work. If you can get you hands on some 12mm, you'd have a little extra safety factor.
2. I cannot think of one off the top of my head.