I have the Strutmaster kit on my '06 GX470 and it rides like a Truck, NOT a Lexus! I'd consider repairing your existing system. eBay has aftermarket electronics shocks for $170 for a pair for my GX (for example). Air-bags run $50-$75 each. If you go coil springs and normal shocks, your electronic suspension and ride adjustments go away (bye-bye). Seems to be a waste of all that factory Lexus technology.