46205 Clone of Freelancer Site with

I want a similar website like the freelancer program by [login to view URL] and the [login to view URL] website but for the purpose of general bidding (reverse Auction style). It should have 3 type of member such as buyer, seller and both. THe ideal site should have feature like browse by country, category and internal messaging to the seller/service provider on the new posting. The member must buy credit before can participate in bidding and in the same time the buyer will earn a certain percentage of credit. Seller can create a Buyer can view the profile of seller. All members can choose to redeemed the credit for money. THe system must be flexible for additional module in future and the a user friendly admin area to control the site.