Marketplace retail script

What I'm looking for is a coder that can replicate the functionailty of Amazon or discogs Marketplace feature. The function I would like is a stanard shopping cart solution with integration with worldpay and paypal, with one central PRODUCT database that is administed by the admin(s) whilst users can submit information for review and posting. The main product database would then act as a central marketplace to enable multiple sellers to see from the one product database, listing their own description/notes, and prices. The database will be used to store and serve a product database of some 500k items ## Deliverables 1) Complete and fully-functional working program(s) in executable form as well as complete source code of all work done. 2) Deliverables must be in ready-to-run condition, as follows (depending on the nature of the deliverables): a) For web sites or other server-side deliverables intended to only ever exist in one place in the Buyer's environment--Deliverables must be installed by the Seller in ready-to-run condition in the Buyer's environment. b) For all others including desktop software or software the buyer intends to distribute: A software installation package that will install the software in ready-to-run condition on the platform(s) specified in this bid request. 3) All deliverables will be considered "work made for hire" under U.S. Copyright law. Buyer will receive exclusive and complete copyrights to all work purchased. (No GPL, GNU, 3rd party components, etc. unless all copyright ramifications are explained AND AGREED TO by the buyer on the site per the coder's Seller Legal Agreement). ## Platform I would prefer the script to be written in PHP on a SQL database (as I do have some knowledge of this platform. However, I am open to toher suggestions which may be applicable to a vast project such as this.