You're definitely right about there being two classes of TIG welders - affordable and workable if a good choice is made and really expensive commercial grade. I've found my Lotos TIG welder to be usable for everything I need to do and I could afford to buy it so that's what I use. Many of the asian welders come with a foot pedal that's inconvenient to use, including my Lotos, so I modified it to overcome the deficiencies. I transplanted the controls onto a used bass drum kick pedal for a rugged and heavy pedal which stays in place (I know what you mean about chasing the pedal with your foot while trying to run a bead) and I further modified the drive to change the control box travel of 30º to a pedal which travels more than 60º using an XL timing belt drive and that gives me finer control of my welding current. The plus is that the pedal works in the usual direction instead of having to position it backwards as you must do with the supplied pedal. It's been working well for me and is rugged enough to survive the typical abuse of a welding shop.
Note to editor: This is already in my builder's page so no need to include it again.