I think I've all but given up on USAKnifemaker ever having much of anything in stock anymore. Unfortunately, I think they're really about the only place that offers (offerED) anything like that.
I believe Great Lakes Waterjet was their supplier for that kind of stuff, though if you want to have them made yourself, I'd recommend contacting Mark Vanderwest @ Leading Edge Fab. Prices are typically a bit better, and turnaround time is unmatched.