Typo capabilities integrated with my rails project

Hello,

I'm wondering what is the best way to integrate Typo into my rails project? I have the following special requirements:

1. Only friends (as per http://agilewebdevelopment.com/plugins/has_many_friends) should be able to see my post 2. Only friends I designate should be able to modify / comment on my posts 3. Need to be able to place advertising content embedded in posts

Is Typo still a good option for this or am I better off rolling my own?

Thanks,

GP