Where to buy aluminum siding?

[TrevorH]

I am trying to weigh some costs on my potential conversion.  Anyone have a recommendation on where to purchase aluminum skin?  I would be building a metal "rib cage" and sika bonding or taping the skin on.  It would definitely be of some structural importance and would be adding a great deal of integrity to the body.  Would you recommend .080 thickness for this or something different?