I TIG welded literally miles of 4" thinwall stainless steel tubing when I worked for E&J Gallo winery in California, using a plain old #11 lens in a conventional welder's hood. What is the reason your current hood supposedly can't be used for TIG? For the past 10 years or so, I've used an auto-darkening hood from Harbor Freight- - - -their higher priced one with adjustable darkness and response time. The only difference I've been able to see between stick welding and MIG or TIG is the fact that there's little to no smoke, requiring a slightly darker lens to filter out all the harmful light.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!