I sold POS systems for years, and never found anything really made for antique shops. There is one I would recommend, though. It will even export to Quickbooks, if that is what you want to do.

The program is POSitive. It is not expensive, and it has a consignment module that will allow you to easily track items in your shop on consignment, if you take any.

You can find out more at their site, where they also have bundled systems with printer, drawer, scanner, etc.

I am not an affiliate, and don't make a peeny if you buy. They have the same folks there they had in the early 90's. Good folks, they look at you as a person, not an account number. If you call them, ask for Dean and tell him Pete sent you. Not for money, just for old times sake.