^^^I did exactly that.
I had my uncle in town a few weeks back. Hes a gen foreman for a weld shop on for navy ships. I had him inspect some of my welds and he said they looked good
I bought a nice mig and started with fluxcore, but have moved to gas now. Read up on it and join a welding forum. theyll help you out a ton.
IMO one of the best welders for jeep fab is the Hobart handler 187. Its super high quality (makes it easier to learn), not horribly expensive ($600ish on sale) and can do 1/4 single pass. It can also do thin sheet if you run gas on it. It wasnt that difficult to learn because it was such a nice machine. I know someone who took a mig course in college and he was impressed by the quality of my welds for just starting out. They were a ton better than his after a semester of practicing on the schools machines. Then he tried my mig and couldnt believe how much easier it was than what he learned on.
IN SUMMARY: Buy a quality mig that can burn 1/4". Hobart/Miller or Lincoln.