There is a supplier called (I believe), Alaskan Copper in Seattle,
Washington, that has sheet, I don’t know about spun copper. My
husband has dealt w/them, however we’re on the west coast. I don’t
know if that is much help for you, not knowing where you’re from.
I’m an enamelist, but mainly use fine silver,(just hate dealing
w/oxides of copper!) Good luck, Lisa