RE: Ball Joint Doll panels: The best place to start petitioning that would likely be Den of Angels. They have a section for events/meetups, and it would be a good place to stir up interest for the panel itself, and maybe someone to run it.
Also, there have traditionally been smaller, more informal gatherings held througout the weekend in the past. Again, DOA usually is the best place to check.
I would seriously consider running it myself, but with running a cosplay gathering and Masquerade on my roster this year, I sadly don't know if I can fit one doll in our car, let alone several XD