I have experimented with many different setups on my 02 3500 2wd. The current set up seems to be working the best so far. I have custom coils (from Coil Spring Specialties, about $200) with a higher rate to support the reunel bumper, and the coils provide about 1. 25" lift. The Airlift 1000 air bags ($85) inside the coils reduce the porpoising on expansion joints and allow me to stiffen or soften the front a little depending on conditions. The air bags at full pressure will net another . 5" of lift. Finally, I am running Bilstein shocks in the front. I have tried 4 other brands and they did not perform well.
That is about it.