use 430ss sheet. It is ferritic (magnets will hold) and it is used in trim appplications, like sinks. Available at:http://www.onlinemetals.com/merchant.cfm?pid=9816&step=4&showunits=inches&id=826&top_cat=0

order online and they will ship or you can pick up in Ballard. $156 for a 3x4 ft x .063" thk sheet. I would hold them on w/ NAS6404 Ti bolts and MS21403-4 silver nuts for a cool space age look.