I got mine from Mazdatrix a few years ago. They've held up pretty well so far, and they're not to expensive either. I probably would have gone with some Widefoots if at the time I thought I'd be tracking it someday. But these have worked pretty well, and I don't know that there's any proof that these won't hold up under track pressure anyway. I guess I'll see eventually haha.
http://www.mazdatrix.com/h93-95b.htm