I have an old stick welder. I'm looking at getting a small wire feed welder for sheet metal and small stuff. What do I want? TIG or MIG. What are the differences and which do I want? Maybe max of $500.00 to spend. I have 220 Vac but 110 Vac would be more convenient. I think I saw an under-hood 12 Vdc once in a magazine a few years back.