You don't need to buy anything. Just crank up the preload on the torsion bars and get an alignment. They do sell "leveling kits" for the 97-03 4x4's but they are just reindexed torsion bar adjustment keys. THey do the same thing as cranking up the stock adjustment keys, which is increase the preload on the torsion bars. THe aftermarket keys just allow you to put too much preload on your torsion bars which leads to premature wear and tear on your front end components and destroy your ride quality.
2005 Expy, 305/45-22 Falkens on 22x9.5 Eagle 026s.
2011 Jeep Wrangler Unlimited, 2" lift, 33" BFG AT KO's on 17x9 Eagle 197s.
2012 Ram 2500 crewcab diesel. 5" RCX lift, 355/60-20 Nitto Terra Grapplers on 20x9 KMC XD Spys.