Berkshire makes 8X. On top of that, their stuff is generally pretty nice, though a little bit on the thin side for my personal tastes. I wish I could remember what the site was where I bought 'em last, they had good prices on 3-packs. I think some department stores sell Berkshire, but they're readily available on several web stores.

EDIT: Aha, this was it! The same place I got the leotards we were wearing as well. http://www.essentialapparel.com/