CS-Cart is the best shopping cart solution for building an ecommerce website of any size: from a small web store to a virtual shopping mall. A ready storefront, support for many payment and shipping options, full inventory control, unlimited products, promotional tools, and other ecommerce software features out-of-the-box.
Demo/Info
http://www.cs-cart.com/multivendor.html
Download
http://mir.cr/18ZHXZEF