delayed funding class signup script

I need you to build a member based script that allows users to signup then post a class or event that will not start until a certain number of people have paid the first month's deposit and agreed to be full time students. This is applicable to classes and events. For example, I have a class I am teaching every week on Monday night at 6pm but it won't start until 100 students have enrolled and paid the first and last month deposit at $100/month. So they have to pay $200 via PayPal and then they can share the class on their face book (with one click send to all friends) and to their email contacts (with one click.) The minimum amount needed to sign up can be variable changed by the event/class admin. Once the minimum (100 in this example) is satisified then the script will start to auto-bill the students to their credit cards via PayPal on the 1st of each month (12:00am on the 1st of each month.) students and event/class admins can virally share the event/class with one click to: all facebook friends all contacts in any email address (aol, yahoo, gmal, hotmal, csv) all facebook friends wall share in one click like a super viral spam machine i only need simple black and white arial 10 text with a place for a log in top left and banner ad in header and footer.