A mig is a LOT easier to learn and makes a good, strong weld. A mig welder with enough capacity and properly equipped can weld anything from thin sheet metal to 1/2" (or more) plate. Other than making sure the metal is clean, it is also VERY quick. You can run a bead as long as you want so long as you have wire and the duty cycle of the welder will take it.
I really can't speak for oxy-acetylene welding. I have used a torch for brazing but I have never welded with steel rod. I really don't think see how a torch could weld with the penetration and strength of a MIG weld. However, I just got a torch from racecarldad and may try my hand at oxy-acetylene welding, just to see hot to do it.
I am saving my money for a MIG welder, though
