Download Manager With PayPal Payments

I currently need a download management system for my Web templates selling site. What I need in the download management script: They Pay with PayPal Admin Panel I can limit how many downloads they can have Have a buy feature and buy out feature - If they buy they get a limited download but if they buy out the item is taken off and they get unlimited downloads Put price on each item Make a different link for the item each purchase The link be displayed after they pay and/or emailed to them after payment For any further questions please PM me. If you have a demo it would be great. Thankyou, Luke