Custom OsCommerce for Elearning

Starting with the latest OsCommerce build, I need several things done. I will later take care of applying the site's looks/themes/graphics, so this in only for functionality. This project is on a small budget and will likely go to lowest bidder, so please consider this. Bare bones coding is all that is needed, and I am a very easy, flexible client to work with. The store will sell online educational courses. The idea is that an admin user with no coding experience can create a new course. The admin should be able to create a "course" (properties: title, completion status)item for the store. The admin should then be able to add "chapters" (properties: title, completion status). Within the "chapters" the user should be able to add "multiple choice questions" and "html pages". Upon completion a printable "completion certificate" should be made available. From the users side, upon login they should see a list of current and previous courses and their completion status on the homepage. They should be able to purchase "courses" just like any store item. They should be able to click a link to a current course, and a listing of chapters will appear. They can then navigate through the chapters, reading the "pages" and completing "multiple choice questions". When they complete a chapter, it is logged in the database that that user has completed the chapter so that they can resume their work at any time. Upon completion, a "completion certificate" is made available when they open the course page. **It is important that the courses are setup so that users that have not purchased courses (or are not logged in) CAN NOT access the course chapters/pages/questions without logging in and purchasing the course! In short, what I need added to oscommerce is: -Admin needs to have the ability create "course" items. -When a user purchases a "course" the user has access for a certain period of time (this should be able to be set from the admin page in "number of days"). -The admin should be able to add "Chapters" within course items. -Within each chapter the admin should be able to create and add "multiple choice questions" and "pages". -"Multiple choice questions" should be a field something like the existing "add product" page with a place for text and html for the questions and a way to add answer selections. -When a user completes all questions correctly, the chapter should be logged in the database as "complete" and display "completed" for that course on the homepage upon login. -Course information must be stored in the database showing which chapters/courses a user has completed, so that when they log in they see their completion status. -Access to current courses (within the above "number of days" time limit) & completion status of current and past courses must be shown on the home page when the user logs in. -When the user "completes" all chapters within a course, that course is marked as complete and "Print certificate" should appear on the homepage. -The admin should include a form to upload "completion certificate" within each course. **I prefer oscommerce, but if you have alternate suggestions that may make this simpler/reduce price please feel free to use your expertise to submit a proposal.