Auto Auction

I have a live auto auction and am looking to be able to post the vehicles for an online auction. There are several scripts available but none do quite everything I need. Basically I need the standard auction format like ebay or similar with thumbnails and at least 8 pictures. I need to be able to treat each customer differently as far as fees charged etc. I want to be able to charge a buyers premium which most auctions available do not do. I also want to collect and process only the fees through PayPal instead of the full purchase price as I would like for the customer to come to the brick and mortar to pay the purchase price. I do not want seller feedbacks and I want any emails between seller and bidder to be confidential so that they cannot get together outside of the auction and consummate business thereby cutting me out of my fees. If I can get these add-ons to a "normal" auction type software, that is what I am looking for.