Show us the rust in the floor and show the upper windshield and the tortion boxes behind the rockers...that will help us give you the best advice
tkorinek in arizona is a good guy to check with for rust free sheetmetal and just craigslist in NV, parts of Utah, Arizona, New Mexico, and Southern California. Also ebay in those areas...the guy who bought the last blazer I had actually found one from Colorado that was about 98% rust free (needed patches in outer rockers,behind both rear wheels, and some work at the rear of the bed area)