Multi-Site Installation

I am looking for support on installing Multisite for my already established website (Buddypress/Wordpress). I am not looking to enable multiple installations of website, however I am looking to make this section into a true directory.

I have read a lot of your documentations/blogs about Multisite, and I would like to know what you suggest.

Additionally, If it is possible to hire WPMU to perform this installation and setup, please let me know what options are available.

Thank you