My info is about 8 years old..
The big Z used to use Gem Creations or Dave Downey. I can't remember
what states they were from, but they would do tours so you shouldn't
concern yourself with their logistics too much. I was never much on
the while you wait aspect of the show though. I may be too picky but
it's very difficult for a bench jeweler to do quality work sitting on
the lease line in a mall with everybody looking over his shoulder,
working with limited tools, after sleeping in a hotel room the night
Now, there's a guy I met in Mexico who cuts initail rings out while
you wait. He can do a nice job in about 5 minutes charging $15. I'll
bet that would pull a nice crowd in a mall.