That's a nice one. Better than my Diversion. I haven't reached the capacity of mine yet, and I've made motor mounts, collectors, exhaust, intake piping. All normal car stuff. If I ever do I'll get a Dynasty and/or a water cooler, because the air cooled torch doesn't last long and it's kind of bulky.
I asked the same thing about helmets: http://forums.hybrid...-you-recommend/
I ended up getting a Miller Professional Series, and am happy with it. Be sure to get a respirator for the welding fumes as well. Chromium 6 is bad. And a full jacket, UV B & C are bad too.
I have a local Airgas that provides me with Argon, can't remember the cylinder size (middle size, largest that fits in my car) but it's 25 bucks a refill (after you buy a bottle), and Home Depot also has them if you need some on the weekend, but it's a few bucks more. You also have to buy their bottle--the guys at Airgas won't take other people's bottles to refill.
This site has lots of disorganized information: http://www.weldingtipsandtricks.com/
Start with plate and just get arcs started and consistent, then add filler, then try a joint. It takes a while to get the feel of how much heat, distance, angle, and speed you need for whatever thickness and joint. And start with steel since aluminum is more expensive and has to be a lot cleaner, and the heat dissipation is something you have to consider as well.