Hi,
I have a Lincoln Migpac 135 and it works great for everything I can do with it. It runs off 120 but requires a 20A circuit. Thin stuff doesn't require much heat. It handles up to 1/4" easily with one pass, too. It has four voltage settings, and infinite feed speed settings. The only thing I wish it had was more intermediate voltage settings. I really couldn't see going to 220V unless you are doing production welding. You get a higher duty cycle with 220 but you pay more for it. Power savings will not be significant unless you weld daily, which is unlikely for most people. If you have a stick welder I say just go for the 120. It is a lot more portable because you can use it with a regular extension cord (12 gauge or better) and you can take it to someone else's garage if you need to.
But if you find a good deal on a 220, go for it.
