How to restrict content via access roles

I'm building a subscription site that will have five sections, each with different content. I need to restrict access to these five sections depending on the user's access role. Each section will need to have its own theme. What's the best way of accomplishing this? (users can be members of more than one access role)

I can't seem to find any modules that address this need. Organic groups seems like overkill and doesn't really address the issue of different access roles efficiently.

Does anyone have any suggestions??