I could never imagine putting anything other than some type of steel or steel alloy wheel on an SUV since they have such hard suspensions. I have magnesium alloy rims on my Benzo and they are soft of F*&K. I busted 2 tires and bent 2 rims hitting potholes this past Winter. I swear, if I have to replace one more $800 rim or another $200 tire on that car, I'm putting some raggy old steel rims with no finish on it.
Don't think there's a way to go bigger and lighter at the same time with a SUV. U want lighter, put a set of those dinky little Scion wheels on your VXThat should make for an interesting (if not funny) looking mod.