For those of you that are local to Greenville, SC, I have found a fabricator that can create custom parts. Alan Pittman Race Cars can custom design and build for your project. They mainly do race cars, but can fabricate most anything you need. Check out the web pictures on the race car roll bars. They have tubing and sheet metal in stock, and can TIG weld aluminum, steel, and titanium. Ask for Alan Pittman, tell him Ken sent you. 1-864-422-0404 Custom parts aren't cheap but his prices are reasonable for the work involved.
Web site link: Alan Pittman Race Cars - Home