I'm going to see what options we have. I know we liked the IP Board stuff, but honestly if I can get a conversion to PHPBB working, that would be the way to go since i'm so much more well versed with it, and their new anti-spam stuff seems to work fairly well. We may have to come up with a better option for things like the garage, but I know there are other ways to go for that as well. I have a test platform I can play with, so may try and pull down a copy of the database and see what I can do for conversions.
IMO, Facebook is a decent place to have a presence, but I know a lot of people still don't like it. So to have it as your forum, you're going to lose potential contributors. I myself prefer a standalone forum like this, even though I do use facebook. I check this a lot more than the facebook forum.
And sorry for the delay. Had to do the honeymoon thing last week