Drupal experts needed

The project is to add new features and modify an existing theme to a website. If I get to choose, it is largely a module development project. The website is built on Drupal 7 + Postgres 9. There are a few custom modules and a custom theme already. The new features should try to re-use existing custom modules first, then use contribute modules, and build new custom ones. The website currently is able to: register a new user (integrated with FB and Twitter), create a binder (it is just a place to hold and organize URLs), upload URLs to binders (when a URL is uploaded, its title, pictures, description tags are auto-fetched by a script), delete URLs from a binder, and share the URLs and the binders between users of the site. A basic theme is developed to display URLs of a binder and binders belong to a user. New features needed to implemented are: 1. upload files and free-text notes to a binder, and display them (this and its theme elements have been partially implemented but they need to be enabled and modified) 2. delete URLs (this has been implemented now but will need to be redone because of the revision history feature below), files, and free-text notes in a binder 3. revision history of the contents of a binder (URLs, files, notes) 4. make a binder public or private (this and its theme elements have been partially implemented but they need to be enabled and modified) 5. for a private binder, its owner is able to permit others to view it 6. make short-URL of binders 7. quota management of files uploaded 8. subscription payment API 9. facebook wall of a user (this and its theme elements have been partially implemented but they need to be modified) 10. add a time-out feature to the auto-fetch script When you reply, please show me what you have done to make you Drupal expert and I should choose you. You don't need to give me a bid amount and project duration now, as I will give you more details of the new features mentioned above if I see a fit. Thanks,