When it comes to ecommerce, there are a lot of platform options. For the best features, back end and checkout, we always recommend Big Commerce. You need a platform that can showcase your inventory, be fully optimized and handle any/all your product variations.
Check it out with a 30 day free trial. I manage a number of stores including one of my own on Big Commerce. We can help you with set up and data load or simply coach you through your build out on an hourly basis. We also offer conversion services to move you and your inventory from other carts (Shopify, Woo, MonsterCommerce, 3Dcart, etc). If you want an ecomm platform that is easy to manage, offers great optimization opportunities and can get your business up and running with Amazon, Ebay, Google Shopping and offer a variety of check out options, including Amazon Pay, there is no better solution than Big Commerce!