Body Parts

[71SWBChevy]

Ok I have a good rolling frame and I am ready to start on the body work on the truck, I haven't done any body work but I have a friend that is going to show me some pointers and help me out so I think I can do it. I am starting with the cab because that is about all that needs to be fixed. The cab needs new supports on the bottom (just the ones that run left to right) and both rockers and cab corners, I am assuming that I need to start with the cab supports and then the corners and last the rockers, is that the right order or should I go a different way with it? Also are there different brands for these parts or are they all made by the same people? If there are different brands which would you recommend? Thanks for all your help guys and I will get some pics here soon to show you guys what I am working with and how it looks after!