Digital download app with paypal integration

Need an embedded application to sell music downloads per album or song just like itunes that is integrated to work with paypal accounts. ? This should allow the whole album purchase for download and quality assurance that the link for download works and customer received it for my records. ? This is just a simple click on album to buy and user downloads it on their desktop after purchase. ? But I would also like to add a shopping cart before purchase. Cool flash design to market the album and display it on the following page for example, [login to view URL] ? I need to collect the market data from users who have bought the album for future advertising as well. ? So database to store the purchase information as well.