A few years ago I saw a small TIG unit in a SS welders shop. The unit was itself SS and about 5 inches x 5 inches and about 18 inches long and easily portable.I own a Lincoln Electric 175 TIG unit and they are huge. Some of the new inverter based gear is smaller, but I can't think of a single reason to travel with a welder, unless that's your profession.
In truth, I dropped $1400 on my TIG and can't imagine a larger waste of cash. I've done some fun projects, but a MIG at half the price would have been a better purchase.
If you really needed something, a little portable brazing outfit would probably do you better.