BuddyPress.org

It actually doesn’t matter if you do it during installation or after… it turns out to be the same.

Have you seen this article:

http://bavatuesdays.com/integrating-wpmu-buddypress-and-bbpress/

It was extremely helpful with my setup and includes the video you mentioned, with some additional pointers. Also read the comment section for some addtional info.

Just make sure you have the latest versions of both and start off fresh. Follow the article I quoted and give that sigh of relief when you switch from WordPress MU to bbpress and see “Welcome admin!” on top instead of “Login”….