BuddyPress.org

Jed, migrating from WP.org to WPMU is not a super simple task unfortunately. It is possible, but you are still diving into phpMyAdmin more than likely.

My advise for a migration is to do it at a time when your user base is low and the database is small so that you can manipulate the data easier.

If you don’t want the blog functionality but *might* want it later, you can still install WPMU and just disclude the BuddyPress Blogs plugin.