Thanks for the suggestions.
I agree that bluegrass and old-time don't really mix well in a session. Completely different approaches to the music. Old-time is about community and sharing. Bluegrass is about performance and showing what one can do. It's my intention to keep this session geared towards old-time, if possible. Though, we do run into the occasional player who thinks that old-time is just bluegrass played slower!
As for where I'm planning to do this: St. Louis, MO over here in the States. Hope it works out!