There seem to have been lots of questions regarding aluminum sources. I think I found a good one. Road Equipment has locations in Michigan, Indiana, Illinois, Wisconsin, Minnesota, North Dakota, Texas, and Florida. I was quoted the following (the cheapest I've found per foot):
Regarding our aluminum trailer roof kits, .040x103", we only offer those in the pre-cut lengths
29' $291.28 part# 1164512
49' $492.17 part# 1164514
54' $542.39 part# 1164517
We do also sell trailer side panels .050 aluminum in sheets
050x49"x110" pre painted white $56.01/ea.
We usually keep 1- 29' roof kit on hand
we have several of the side panels on hand.
Any questions, or concerns please call me at the #'s below or e-mail me back.
I'll be getting my axle through them...Dexter 2200# with brakes, $350 (without brakes would have been $230)
I hope this helps someone,