Typo capabilities integrated with my rails project


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
  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?