Amazon and eBay Shopping Software

We are looking for somebody who has knowledge of using Amazon and/or eBay’s API’s to create a piece of software that allows users to pull a specific product listing from Amazon or eBay, put it into a shopping cart, then purchase, all through the Web Application. The user can choose to either search Amazon using the ASIN and price, or search eBay using the unique eBay Item Number. Once the search is made the user is shown the information from the Amazon or eBay listing to verify it is the correct item. Information will include the title, the price, the description, an image if available, and the ASIN or eBay Item Number. Once they verify the information is correct they can add the item to their shopping cart. Once they are done shopping, they can go through the checkout process. When we get to checkout, everything for amazon and everything for eBay will be checked out separately. Using the API the software will verify if the products are in stock, then go through the purchase. We don’t want the user to have to leave the software at all through this whole process. All purchases are going to use the same Amazon and eBay account. The user will not log into their own account.