Hey man,
I have honestly thought about this myself. I love fabbing stuff on my Jeep, or for anything for that matter. I don't' know how the market is right now, but I can tell you people don't seem to be dropping coin like they were a year ago. I don't want to discourage you, I think what you are doing is a dream of mine I would like to see happen some day, but you should probably open your horizons to JK stuff too as that is where the market has really shifted. Make friends with a jeep club, guys that are buying JKs and wanting to mod and wheel the crap out of them obviously have $ to blow, so if you have something to offert them, you have your "clients", with the cash to spend on your stuff. I have an XJ (94) that I am not doing anything with right now. It is not registered or insured, and I have big plans for it (some day). I would be willing to let you keep it as a prototype vehicle for as long as you wanted if you need something to fab stuff on. Shoot me a PM if you want to talk details there. I would also be interested in helping you in any way possible. I have a MIG welder and a few tools, nothing much though. I have also thought that being an installer would help in slow times, if you could install lifts, tires, and other parts. You wouldn't have to be a real mechanic, no engine stuff, but bolt on stuff that people don't have the time/skill/tools to do themselves. I think the market is there if you are creative, innovative, and open minded. Like I said don't limit yourself to XJ's & MJ's, we're the cheapo's. Certainly make awesome parts for them, but don't plan on feeding your family from that alone. Love to chat with you more about this so PM me if you get a chance.
Jon