I have a '01 4.4i, Turner Motorsport front control arms with the bearings, Caster camber plates, Polyurethane bushings throughout the rest of the suspension. H&R front lowering springs, rear air bags and 20" style 87 wheels.
I put Bilstein B6's all the way around and I can't wait to take the rear ones off! The truck handles excellent, the front feels perfect but the back bucks every time you hit a little bitty pebble! I contacted Bilstein, they told me you can't run the B6's (on the rear) with airbags on an X5. And they won't revalve them for me! I'm going to try B4's.