Has anyone implemented a point-of-sale and inventory and vendor management solution?

We have researched eposly (native Salesforce app) which provides some of the needs we have, but basically:

1.) Need a way to track purchases of retail product for sale, the associated vendors, cost, on-hand quantity (normal retail metrics);

2.) Provide a mechanism for selling the products via "store credit" that adds to a running total (per individual) that is rolled up into a "family total" at the end of a week;

3.) This total should be itemized, and clear, along with any other charges already on the "guest folio."

4.) Standard reporting metrics for sales by individual, demographic, time-period, vendor, style, etc.

5.) Nice-to-haves would include size-style matrix (attributes) pricing, purchase/receiving/inventory process, and easy-to-enter sales associate interface.

We are committed to building internally, but if there are building blocks already in the wild, I'd love to hear your thoughts.