Controlled Auction Site

Looking for the development of a "controlled" auction site. This site will require all listed products to be authenticated by site owner prior to auction being able to launch. The Site is focused on only one type of product with unlimited sub categories or "unique items" that can be sold (an example would be a site dedicated to the resale of collectible stamps, each item will belong to a category such as the country of origin, then below that would be an unlimited amount of unique listings. Site must have the ability to reflect value, % discount and price for each unique listing. In addition a buy it now option needs to exist. Looking for integration with Paypal and all other major forms of payment. Would like the ability to search listings by sub category, discount and list pricing.