You may be interested in what other options are out there for commerce and Sitecore. There are 3 ways you can go:
1) Use CommerceConnect with commerce packages like InSite or Magento etc.
2) Use uCommerce which use CommerceConnect but also integrates with Sitecore via the ItemProvider, giving you full access to all the Sitecore marketing features.
3) Sitecore Commerce which is a big enterprise commerce platform fully integrated by Sitecore and built by Sitecore.
Not sure which is right for you, email me at firstname.lastname@example.org and we can get you connected with the right resources.