Precision Chassis Works in Gilbert (www.precisionchassisworks.com) does excellent quality work. Web site has lots of cage porn. He hasn't done a whole lot of rally cages (few people in the area have), but he's done at least one that held up very well in a pretty nasty incident. I can't remember the name of another guy (who I think is in Tempe) that did the cage that was originally in my car, but you might try Doug Chernis at Race Technik in Mesa (www.racetechnik.com), and see if he knows. Now that he has a larger shop, he may also do cage fabrication.
If you know what you want, there are lots of places that can do the work, but there are relatively few places in the country, and probably none around here, that will just take a car in and put in a cage of their own design that they guarantee will get a log book, unless you are willing to pay for their time to research it.