I think there are a few other sources for good cat frames in the PNW, but being in Boise your best bet may be a Payette River Equipment frame. They are steel, but painted and that is what a large percentage of the Boise area North Forkers run. Even though they are steel they are really light. I'm not sure if this is the website for Ronnie or Ted, but even if you get ahold of Ted he'll send you to Ronnie who is the one who makes the frames. As I recall, they were in the range of $500 or so.
Payette River Equipment. - (20 283-RAFT
Edit - I see that is Ted's email but I'd start with him.