Personally I would do it myself, you can get a hydraulic tubing bender with dies from Harbor Freight for cheap. When I say cheap, it would run about what a pro would charge you to bend all the pieces you would need for a cage.
Get friendly with someone who works at or owns a muffler shop, in a pinch they can make anything out of tubing you might want or need.
I agree with jstandle...you've got a heavy rig and I would not recommend skimping on a cage to save a few bucks.
I would think that any of the race shops geared toward the roundy-round cars would be set up for tube work, in addition to any of the serious 4x4 shops or desert race fab shops. Have you tried the yellow pages?
I did a Google and found a guy that looks to be doing this out of his garage, but I'm sure there are lot's more. Sorry I don't have any personal reccomendations...I bought a Pro-Tools 105 manual bender and love it. Good luck and build a sweet cage.
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