Custom Shopping cart and more

I want to make a custom store to replace my current setup. Visit [login to view URL] to get an idea of the current setup. The point of the website is to sell lecture notes. The following features are required: 1. easy sign up to make your "own store." 1a. you can upload your digital documents in word format and the server will convert to pdf adding a message either as a cover page or as a header/footer (once you accept the project i will tell you the message. 1b. The seller will be able to create categories if they do not already exist. (only classes with in a school. the programmer will need to setup categories for the major US universities. Teachers and classes do not need to be setup, but should be easily created by the seller as necessary). These categories that are created can be used by other sellers when they upload their notes. 2. All products from all sellers will be accessable through the main page. There is no clear division between stores--ie the digital media all appear to come from the same place. The broswer will be able to search the store by "seller" and by categories. 3. Affiliate program: each seller will recieve an affiliate link. They will recieve 10% of all sales they generate for the other sellers on the website (example: if person A visit the website as a result of Seller X's notes and decides to buy person As notes and person Bs notes they will recieve 10% from the sale of person B). 4. All sellers will be charged a 20% fee by the "mall" (ie website) for every sale they make. (this will be the fee to have their website hosted). 4a. The seller may choose to pay a yearly fee and avoid the commision fee (i would like this option implemented) 5. The ability to transmit digital media upon payment recieved via paypal. 6. All affiliate sales/commissions should be made through paypal. 7. The website should be seo friendly 8. The seller can have individual cupon codes (ie codes only work for Person A not B's notes). The seller can make their own price. 9. The shopping cart should charge the following tax (2.99% + .33 cents of the total order) [and the tax should say "Paypal Fee". 10. Trouble ticket system (each note taker should be resonsible for their own tickets.. i e person As notes should have their own trouble ticket). 11. A news page (that automatically updates every 24 hours displaying the most recent notes added and linking to them). I hope what i am reqesting makes sence. If you are confused in anyway please message me for clarification. I have the following scripts at my disposal: sunshop 3.5, idevaffiliate, and trouble ticket software programs that come in fantastico. As to the design: you can keep the current design or propose a new one (quote me a fee and a mockup if you wish to make a new design).