I would drop Golds gym like a bad fucking habit if T-Gym opened up. Holy shit.
But about a "Fatties Gym" I don't really think it would take it, but what do i know?
There are already a bunch of fat people going to the regular gyms, so I don't think the atmosphere is the problem.
Whatever you decide to do... Get the information out there. Have pamphletes about how to lose weight safely...About the "Top 10" exercises you can do. Stuff like that would help out.