It would also depend on the date. As I said in the other thread, the first week of August is WBC out in Lancaster, PA.
Going to another event in August is problematical. Plus, it will be tough for Djensen to make your event if you end up picking the weekend of August 15-18. That is when Gen Con Indy 2013 happens and he has already stated that he is going to it.
I would also think that anything near that would be tough for him unless you go the weekend prior and he just makes it an east coast, week-long roadie.
I know my suggestion of an October weekend has issues too, specifically Canadian Thanksgiving. I have always thought that Fall A&A Gathering would work around the Columbus Day weekend here in the states, but I do realize that it would then exclude the Canadian participation.
Maybe a late September date (riding on the coattails of and/or working in conjunction with an Oktoberfest festival) would work better. Just spitballing.