I have a few questions on what to do on my 63

[Strykerta]

I have the body off my 63 stepside and im going to take it to the blasters soon so i can get this project moving. Ive been doing alot of research but was looking to see if theres a good pool of info for my questions that i cant solve..
1) i am trying to find a 5 bolt disc rear setup that will fit under this im not afraid to cut and weld all my perches from this stock onto the newer unit im just not sure if theres a specific year to look for with the same wheel base?
2) is there a good starting point on how to build my own air suspension for this truck. Im not the type to go out and buy a premade system id rather save the money and waste the time learning myself but need a few pointers how to get it all going and what products are best for the buck.
3)i have alot of body panels to repair and partially replace mainly the whole lower floor. is there any place to buy quality panels other than lmctruck?
4)one other question is what offset rim does this truck use? im planning on throwing atleast 18x8's on it.

Thanks for all your help. Ill post up pics soon.