I would suggest you have a look at HTP's HTP130DCHF.
http://www.htpweld.com/products/tig_welders/tig130.html
I have used it on projects ranging from 18ga to 1/4" steel.
It is small, lightweight and portable (about the size of a toaster).
It provides 5a-130a (inf. adjustable; 15% duty cycle) of DC rated at
3/16 steel.
It has built-in gas solenoid (no on-torch valve), HF start and lift
start.
It includes a solidly built foot pedal (12ft), torch and ground cable.
It requires 230v (16a max) and can do stick with an electrode holder.
The HTP130DCHF sells for $850 (includes flow-guage) and has a money
back guarantee. BTW, you will not find better support than the folks at
HTP.
I have purchased several welders from them (as have my friends) and
strongly recommend them.