There is a place called Music Lab in Austin (they have 2 locations) which was perfect for the last several ampfests we had there. There will be one again around the first weekend in November. Most of the talk about it is on Harmony Central though.
I'd go to Austin if there was one there, but I don't have the time to make a trip to Dallas. I'd bring a Diezel Herbert and VH4, a Bogner Ecstasy and a Mesa Mark V head.