Multichannel E-Commerce Order Management System Required

We already have an [login to view URL], [login to view URL] and Magento online store. We need an order management system that will process all orders quickly and efficiently (using integrated labels, etc) and controls inventory. We tried one system, but it did not work and customer service was zero (it was an Indian software company surprise surprise). So, we are looking for someone who can implement an order management system that works and is easy to use for people who are not in I.T.