Being that I make my living as a fabricator I will kick in my 2 cents.
First will you need AC/DC/ or just a DC unit meaning are you just planing on steel or you going to feature into Alum also a nice DC unit is cheaper than a AC/DC unit. I have 3 different Tig units
1. I have a little HTP 130 amp DC unit..... very portable only use for steel can take it any where will do any thing you need to do with a motorcycle.
2. I have a Lincoln 175 square wave AC/DC not as portable but is on wheels, use it the most.
3.Setting in the corner is a Lincoln Idealarc 250 it is a older machine but I use it for precision project that are built on the work bench.
I don't know how much experience you have with a tig welding, but a lot of comm. collages have welding programs. You can usually take just a tig class.
