create a Market place for electronic files website

Here's what I want to achieve: A website where people can sign up to sell electronic files. These users can register at the site and be able to sell their efiles for download. They will set the price for their files (with minimum set by the admin). There will be commission from each sale. Sellers can generate reports of their sales. Buyers can also signup to the site and browse the files to purchase. So a shopping cart needs to be setup. ecommerce script like oscommerce or zend can be used if there's a mod that can do this or if you can write the mod for it. After purchasing and successful payment they can instantly download their purchase or email a link to them where they can download. So, there will be a need for credit card processing and paypal payment. The functionality of the site will be based on ebay but it will NOT be an auction site, more of a market place for downloadable files. There will be ratings and comments to members. Price is set by the SELLER. I will need an admin panel that can: - Monitor items being sold - Generate reports of sales - View reported abuse - Mass email members by category (All sellers, All buyers or both). Other modules: - Affiliate program can be integrated - Forum integration (phpBB or vBulletin or SMF or PunBB) Thanks. If anything is unclear, just PM me.