The problem with going lower than 4 inches is that there is not a big enough "window" for the steering components during full articulation. Solid axle frames have a "hump" at the front where the IFS frames are basically straight. This hump gives 2 additional inches of clearance for steering components on compression.

If you run normal crossover steering (not high steer), use bumpstops, and get a pitman arm with less drop (available from OTT Industries or Sky Manufacturing) I think that you could get away with 3 inches of suspension lift. You could run the FROR hanger with stock Jeep Wagoneer springs to accomplish this without having to shell out money for custom springs.