How drastic do you want to go? Check out these sites. Lots of pieces parts and info. If you want to retain the leaf springs (which will work fine) using the Nova rear rails from Autoweld would get you close and you can fab the front brackets or pick them up from Speedway.
http://autoweldchassis.com/spec.ivnu
http://www.speedwaymotors.com/
http://www.suicidedoors.com/
Mark