Digital/Downloadable items shopping cart (phd/mysql)

I am looking for a website based on an excisting CMS system such as Joomla, Drupal or etc. Or possibly as an add-on on an open source shopping card system. The function of the website would be exactly same as t he following websites: [login to view URL] [login to view URL] Which users are able to sell and buy digital items such as 3d computer graphic files and models, the owner of the website through the back pannel should have access to all data and details, user information and orders detais, no files to be shown on the website perior of the administrator approval. The users will have their own ocontrol panel to track their orders and financial details. The website owner will be able to deduct and receive a prercentage of commission form user or bill them with the calculated amount. Please check the provided websites for more details, making a test user account is advised to findout about user control panel possibilities. Security and spam controlling are needed to be implemented.