weeg,

You didnt mention if you can gas weld, if you can do that, Tig isnt that much different, its just that you have to learn to manipulate the peddle for the arc.
I use a thumb controller on my tig and works great for when you have to get into tight areas.
I use it to weld sheet metal but you have to learn to go in small
increments , just like when you use Mig.
I also use silicon bronze rod , as it melts at a lower temp, therefore eliminating some warp.

I bought my Tig unit used for 800.00 bucks from my local welding store. It my be old but works like a dream. I bought a book that tought me where to set the machine for Steel & aluminum, and tought myself.

I also have a Mig welder too but i find i like my Tig alot better.

SprayTech