[HO455]

It sounds like a pretty ambitious project for your experience level. I agree with the others and endorse looking for a better body. At least until you get some more experience. Maybe find some one local who has the experience and is willing to walk you through the project. If you find one with better floors and body mounts, you could then start building your skills by doing the rockers. Front rocker replacement is fairly easy and there is lots of information out there to help you. (Suburbans have some rocker difference's but they are pretty well documented.). There are some tools that will be required, as well as a boat load of patience. Also be careful to check for cowl rust. It can be a real challenge to fix.