Madasooner: There are a couple threads going on about rear suspension. if you have the time check through the Armada Rear Coils thread I started. TONS of info! In someways you are ahead of the curve in that you already have the stiffer non-tow spring (unless there are three different ones... lol) you could prolly skip to the last handful of pages on that thread. Firestones (Blue bags) so far are showing more promise than the AirLift1000s (Red bags). Pops can attest to his experience with the AirLifts and I believe E&J Pushin' Wind has the Firestones... I know Grill has the Firestones, but he is about to have a bunch of work done by Greg (PRG Products). Pops' suggestion on bump stops is a terrific one, other things to consider if that doesn't get you to where you want to be is to add stiffer/better rear shocks, possibly upgrade rear coils (not sure if it is an upgrade for you or not), add helper airbags (Firestone or AirLift.... your call). Most have done exterior manual fill on the helper airbags.
If someone can chime in on issues of in-cabin/exterior fill that would be terrific.
'05 Mada LE Slate
Mods Done: UpRev, Bilstein 5100s in front, PRG 2" rear spaces, R1 Premium Drilled & Slotted Rotors, PosiQuite pads, Volant GenII CAI, 8K HID Lows, LEDs by ArmaDen, 3k HID Fogs, and Delete middle row console.
Mods in progress: JBA LT, PRT 300-cell hi-flo cat'd b-pipes, Borla xlr-1 muffler w/custom tubing, LED Engine Bay LEDs, Custom Suspension Lift by PRG, Custom PRG front & rear shocks, Custom PRG Rear springs.
Mods in contemplation: GoodHood or custom hood, Steel front and rear bumpers, upgraded front springs, Custom roof rack and cargo basket, Additional lighting.