I understand your situtation… WP eStore like any other plugin requires the logged in user to be admin before they can make any changes.
You can’t assign a particular use to have access to eStore but what you can do is make eStore menus available for any logged in users. This way both admins and editors will be able to use it.
If this solution sounds feasible then let me know and I will tell you what tweak you need to achieve this.