We make our own. This is the best bread ever and is incredibly easy. It's written for a bread machine but you can do it by hand, with no kneading or magic, and it comes out great. I use the millet flour, not oat flour--we just like that flavor better.
http://glutenfreegoddess.blogspot.com/2009/02/delicious-gluten-free-bread.html
If you like baking, I urge you to go for this. Did I mention it's super easy? If you don't want to bake your own, then +1 for Udi's at MOM and +1 for putting things in corn tortillas. Those are our backups.
All gluten-free bread should be kept in the freezer until you use it. You can defrost in the toaster. (I actually just make everything on light toast, pretty much.) In the grocery store, you'll find it in the freezer case.