Advertising Website which can accomodate financial transactions

I cannot go into to much detail initially until a confidentiality agreement is signed. Basically this website will allow people to advertise items which will be purchased with say 10% of the sale going to the website owner. It will need the ability for someone to be able to become a member of the site and upload their lisiting themselves. Similar to [login to view URL] I guess however with part of the transaction going to the site owner and it being a very very specific product which will be sold. I am still working through some of the detail of this project but essentially it is innovative enough to ensure that it will create it's own market. I am happy work on a profit share arangment if someone is interested.