I live on the Wet Coast, so I can't really help you. What I can tell you- as said above, Rancho, Scott at Metalcraft or Gary Berg all can build a serviceable gearbox, but if any of the somewhat more 'local' recommendations work out it's the better route to go. You'll save the freight ($200?) each way across the country and that freight charge (each way) will be there AGAIN should it have to go back (and even Rancho doesn't get it right EVERY time).
Dealing with someone more local can be more satisfying, as well- if he's close enough you may get to see it go together and may even help with disassembly and inspecting/washing parts, your money will stay in the local economy and you're helping build the local scene. There are guys in your area that know their way around these things- you just have to find them. Check out the local VW clubs and shows, as they're out there. Al