We opened a restaurant/lounge/concession stand out at our practice facility. We've got a concession stand with popcorn, drinks, candy, etc as well as a sit down restaurant with full menu and a lounge. We have 2 tills in the concession stand that connect back to a server than runs a MySQL database. The tills are the same kind as you'd see in a gas station, touch screen, a handful of USB, RJ11/45 and serial ports. They're made by radiant systems. The cash drawer is kicked out via the RJ11. It's got an integrated 3 track card reader. The tills in the restaurant/lounge are the same ones. We use the same ones at our main location for our 50/50 system and for the merch booths. They're really solid, spill resistant, and reliable. We've got probably 40 of them total between all spots and in the 3 years we've had them, I've had 1 power supply die and 1 hard drive die. They all run XP embedded. We're using the Epson TM88 series printers, which are pretty much the industry standard.
They're the ones we use for both the software and hardware side for food, and hardware only for merch and 50/50. We use the quick service for concessions and table service for the restaurant/lounge.
You need a box on the back end that will handle the DB, and they can all run off the same network. When we put it in, the table service/quick service DB's were able to run on full SQL, but only on a 32bit version of windows. I suspect they've changed that. To each till, you will need network and power. If you go integrated debit/credit, you need a single line, if you go with stand along credit/debit, you need a second RJ45 or RJ11. Keep in mind with credit and debit you need to have a PCI compliance plan in place as well.
This is who we use, there's a hundred other guys who do the exact same thing software wise, for hardware, there's not that many makers.
I went all over the place with that info, if I missed something or you want to know more, let me know.