There's a brand you can find here in Madison called Bob's Red Mill (they make all sorts of flours) that I've found in the flour aisle at most of our larger supermarkets. Also, if you have any Italian specialty markets in town, they should have a selection as well. Before you buy, though, double-check that the level of coarseness works with what you're making. It's usually available in various levels from fine to very very coarse.
Hope that's some help.