Develop Magento plugin

We would like to invite bid to develop Manento plugin for our website www.crazypets.in. This plugin will enable multi vendor support in existing website. Few of the features that we need are- Enable multi vendor to list their products that may belong to same category,manufacturer and the website also list multiple prizes and individual seller rating(similar to [login to view URL]). we also need thsi module to provide multivendor drop ship functionality where each of them can manage their inventory,prices, packaging,shipment,returns,offers separately.