Blue Link is a fully integrated ERP solution with robust accounting, inventory and POS features. www.BlueLinkERP.com
You're not likely to find a cloud accounting solution that offers inventory and POS out of the box. Your best bet is to find a solid accounting solution that integrates with different inventory and POS solutions. One option to consider is Xero. Xero a standalone accounting tool that's gotten praise from a bunch of sources, Business-Software.com included. It offers a selection of inventory and point of sale plugins, so you can evaluate your options. Good luck.
QuickBooks online has inventory tracking features, and you can more than likely find a POS plugin through app add-ons. Depending on how large your operation is, though, you might be better off looking at cloud ERP solutions rather than focusing on strictly accounting solutions?