RV Repair: Leak Damaged Popup Camper, pop up camper, water damage

Question
I have recently aquired a 1990 Starcraft Pop up camper that had been partially disassembled for repairs,I had to finish removing all of the wood panels in the top of the camper and I have water damage on almost everything inside the camper, my question is, when I figure out how to repair all the water damage, Where do all the attachments go for the sides and top?
 I have not gotten the top material figured out yet but, I am thinking of the RSP board for the replacment ceiling board. What is your thought?
 I want to make sure that if it ever leaks again I won't have to wory about it falling on my head.
And I need to find me some Textured Aluminum for the outside of the camper. Where do I find this in wider sheets?  

Answer
I'm not all that familiar with popups.
I would suggest calling Starcraft customer service. They can tell you what materials will work best for your repairs. They probably have a parts department that can sell you the parts you need, or direct you to somewhere locally that you can purchase them.
Dave