I had paid for Jooma's JomSocial which is full of bells and whistles but it was really inflexible. I'm so happy I found BuddyPress which is simple and very easy to customise. There seem to be some great add-ons for this too. I had to ask for support for initial template integration and I have to say I haven't had amazing support like that for a LONG time. I would highly recommend this plugin!!