ChannelSale is the way to go. I may be bias here because I simply love this ecommerce solution and been using it for over 18 months now. Have integrated my Jet.com store with Amazon and eBay stores.
Very smooth and quick integration process. And the platform is fairly simple and easy to use. And it’s all affordable. So while one part of me will vouch for ChannelSale and tell you to go with it without any second opinion, my other part will say that you can look at other options. But be careful here. Compare their features, services, pricing, platform carefully before you go with anyone.