Another good option, is look for a used pro level welder. For instance, I have a Hobart BetaMig 250 that I bought on ebay. With shipping, it only cost my $750 and it's a 250 amp, 60% duty cycle welder. Heck, I use it in my fab shop. Alot of times, you can get a very heavy duty welder, with some nice accessories for the same or less money as a new, light duty machine. For sheet metal, having a welder that uses shielding gas is key. I don't care how expensive the welder is, if you're using flux core wire, it WILL burn too hot and you WILL have a terrible time welding thin stuff.
Another side benefit of getting a pro level welder, is that for the major brands (Hobart, Miller, Esab, ThermalArc, etc) your local welding supply will have a large selection of parts in stock.
FWIW, Hobart and Miller (same company now) are THE ticket for entry level to medium duty welders.... Lincoln just doesn't have the arc stability that Miller/Hobart does.. On the heavier stuff, they all are good choices.
