I just started managing several online bookstores which all have the same inventory. Currently, we're using Fillz integrated with Chrislands to manage inventory across all of the sites, but I'd like more control over the individual sites than Chrislands offers--ideally through WordPress.
Is there an inventory management system that can integrate with multiple WordPress sites? For example, I need it to remove a book listing from all sites when that book sells on one of the sites. It would also need to be able to auto-upload and manage inventory on Amazon, eBay, etc.