Autotrader portal site

The website that i am looking to have developed is a autotarder portal site. Data base driven where by people can advertise their motor vehicles online, payment gateway is email by invoice, search for a particular make and model etc, edit / delete advert/s advert expiration fuction, sites of interest include : yahoo autos, MSN autos, [login to view URL], [login to view URL], [login to view URL] Please advice your quote broken down in programming and design charges. Programming experience is of most importance. Please list only revelent experience and only sites that would be of interest. We are looking for an offshore programming / deseign company to be able to work with on a number of upcoming projects. Look foward to your thoughts, comments and recommendiations