Hello, for this I recommend OpenCart. It's fast, free, and has a much shorter administration learning curve compared to other software e.g. Magento, CS-cart, etc. In addition, most of the features you describe are builtin. My job would be to develop the custom features. I have worked extensively with OpenCart including developing custom extensions and modifying the software to support adding millions of products. I'm very familiar with their MVC architecture, so I'm able to develop professional extensions that other programmers are able to understand. I understand your project and I can get started right away. I guarantee I can do this in less than 7 days. I'm available on a variety of instant messaging platforms including Skype. And I'm available every single day. If you need more information, please feel free to ask away. Looking forward to working with you! :-)