What materials should I use for an Observation Deck

[garbemi]

I have a 1988 Blue Bird school bus that I am transforming into a tailgating/nascar bus. I want to put a deck on top of the bus along with a porch on the back. What gauge square tubing should I use for the supports on the deck? also how do I need to attach to the rails on the back of the bus and with what material? Any help would be greatly appreciated maybe even pictures thank you.

War Eagle!!

[garbemi]

ANYONE?

[TheRainbowBoxer]

There's several buses on here that have had this done. I like this one - http://www.skoolie.net/forum/viewtopic.php?f=9&t=5517

Not sure if he goes into specifics on his materials, but it is well done.