Are there any part numbers on your current shocks? They often have them stamped in during manufacture. You should be able to determine the compressed and extended dimensions fairly easily (travel), so weight would be the unknown. Also believe there are recommend shocks for various modifications. Is everything else basically stock, engine, axles, etc?
Edit:
http://www.shockwarehouse.com/news/p...ck-lengths.pdf
http://www.shockwarehouse.com/news/p...ck-lengths.pdf
Might call one of the shock companies (after you have the shock measurements) and ask for there recommendations.