If you are looking for a 110V unit, look at the Lincoln HandyMig series. I bought one from Sears online, and love it. It's 10 times the welder than the Chinese one I had before. It will go flux or gas, I have only used flux on mine so far. Only thing about gas is the regulator doesn't have a gauge, never understood why that is. I bought a gauge to put on mine, just haven't ever gotten around to getting a bottle for it yet.
I would love to have one of those Millermatic jobs, but they were out of my price range. If I need to weld thick stuff, I just break out my rusty trusty Lincoln stick welder.