Due to the restrictions of my cabinetry I cannot use premade island support such as those by Chemical Concepts. At least this is what the installers tell me! I have to buy flat bars of steel from a steel manufacturer. Here is where I get stuck! Should I buy stainless steel or regular painted cold rolled steel? SS is rather expensive and I am concerned that the painted cold rolled steel will still rust. The flat bars will be sandwiched between the plywood underlayment for the 2cm granite and the granite.