Build an Online Classifieds Store with escrow option

Online store where users can buy and sell goods through escrow service with Bitcoins The idea in brief: Peter wants to sell an item. He publishes it at our website - photo, price, shipping option (if it is not a digital good), etc... John needs this item. He search at our website and see the items, the seller's feedback, etc...He decide to buy from Peter. Then deposit money to his account and click buy. The money go to third pary - person / escrow and they are safe, cause they are not available to seller and to buyer. Peter see the the money are in the escrow and the address of John and sends the item. John receive the item and confirm it's ok - the money (-some proof for us) goes to Peter. or John doen't receive the item - dispute - (more work for us, more proof for us), we decide where should go the money. More info when I accept your application...