I'm planning on getting a 220v wire-feed/MIG for heavier work, but it's nice having a machine that has a natural operating range that's right for sheet-metal work. My Clarke has four different power settings, and it can burn through 16ga. sheet steel on the second-lowest setting if you're not careful. You can also always run multiple weld passes (which my welding book recommends even with 220v machines for heavy material).
The big-box hardware stores and farm stores around here do carry 220v welders, both stick and wire-feed. Obviously you can get even fancier stuff at a dedicated welding supply store.
