Plugin development for Wordpress

I need a plugin to give complete support on WordPress to a reverse auction website. The plugin should support users as vendors or buyers, the complete process of the reverse auction behavior on each product being sold and the option of not just bid but also buy the item directly. Each post should behave as a reverse auction. The reverse auction process will be clarified if there is any doubt about it. Please state the fastest time frame you can reach. Any other details will be provided prior request.