I wouldn't suggest an Exo Terra for a Ball unless your willing to spend a little extra money to make proper modifications to it.
If you do use an exo terra one thing you will need to do it either replace the screen with a piece of PVC or HDPE board and use a radiant heat panel instead of CHE's, uth's or lights. This way you could keep a better hold on humidity and temperature.
I'm in the process of setting up a new exo terra 18x18x24 right now. I will post pictures once its completed. Gonna take me about another two weeks to complete since I'm making my own background out of spray foam.
As for a stand I just went to Walmart and bought a basic square black end table.