Steel studs

For some reason, I always have to be different. Has anyone tried using steel studs spaced 1 ft apart with a thin fiberglass or plastic sheet on each side in place of plywood for the sides or top? This seems as though, if constructed correctly, would be lighter and as strong as plywood. Cost my be higher though but not oo much. Would most likely need a solid steel cross support for the rear hatch--no problem.
My other thought was to weld up and aluminum skeleton but AL is just to pricey.
Just want to be unique.
My other thought was to weld up and aluminum skeleton but AL is just to pricey.
Just want to be unique.
