A body lift uses grade 5 bolts, it allows the bolts to bend, a grade 8 or higher would snap. You really can't tell the diff between a 2" and a 3" unless you have the 2 side by side....
I am not a big fan of body lifts, but they do the trick, and they are fairly cheap. You can do this now and save for a spring lift, or a shackle lift (daystar makes a nice shackle). Get a 4" kit from Skyjacker, superlift, or rubicon express. They all make nice kits, just make sure you read all of the directions or have someone install it for you.
-James