YOU DON'T WANT TO OXY/ACET. You'll warp very bad, and it's hard to get good penetration w/out making another hole. You can't weld w/the cutting tip, you'll need to get some different tips. Plus, it will take you a good while to get good w/it. On the mig, pull the trigger, and you'll learn how to run a good pass quick. You'll have to play w/wire feed speed and heat, but a good starting point is to start w/low to mid heat, then set the wire speed low. Start w/that, and slowly increase wire speed until you can see the wire melt right @the point of contact w/the steel you're welding. When it's set right, it'll sound like bacon cooking, or a really loud bee or wasp. It shouldn't have any interruptions in the sound, like the wire 'catching up' to the amt of heat you're using. I know this sounds foreign, but once you pull that trigger and get to playin w/it, you'll understand what I mean. I've been a fitter / welder for many years, so any questions you have, post away.
Chk out Lowe's. You can get a very good wire feed welder for around 3 bills. They're gasless, but you can buy a kit to add gas for about $100 (which is good for heavier guages of metal, but for sheet the non-gas welding is good). You can play w/the fluxcore wire that might come w/it, but you want to weld w/solid wire. Fluxcore gets way too hot. Strong welds, but you don't need them that strong for what you're doing. Another little hint; if you're planning on welding stainless to carbon (regular steel), you want STAINLESS wire. Carbon wire will make the joint very brittle, and will break.
John Milliman, my fav nickname for the torch is Fire Hammer....
