Wordpress customization (programming)

Hi, I'm using this theme [login to view URL] on my site and it charges visitors a fee to post a listing. What I want to do instead is offer memberships where a certain amount of listings are included. The theme doesn't work with s2member right out of the box because members who sign up via the theme are assigned to a custom role called "agent" and s2member assigns members its own roles ("s2member level1" s2member level2" etc). WHAT I NEED: I need the simplest solution possible to offer memberships with recurring billing. There might be a plugin that works with this theme or you may have to do some tweaking on s2member. The solution should handle upgrades, expirations etc automatically. I also need to be able to set a post (listing) limit to each membership level (maybe using [login to view URL]). IMPORTANT: Please discuss about this specific project in your proposal and mention how you plan on accomplishing [login to view URL] typical copy and paste proposals with tons of links to unrelated previous projects will be IGNORED. Thanks. Looking forward to working with you!