Lucas Fab in Huntington Beach through Hergesheimer Motorsports did mine to my design and I couldn't be happier with it.
http://forums.pelicanparts.com/porsche-autocross-track-racing/633095-new-911-track-toy-build.html
Mine was ~$6k but I went over the top with it. If I had stayed inside of the firewalls, it would have been about half that and mig vs. more time consuming tig and mild steel vs. 4130 would have brought it down even further.