I avoid any big chips labeled 82XX.
Keyboard or Keypad circuitry is simple and generic... go to a technical bookstore or a university library and check through some of the diagrams. Actually, the internet may be faster.

7 Segment LED displays are easy. If you have a Radio Shack store available, they have some simple hobbyist books on how to hook them up.

If you were doing a production design, I'd recommend a great part but it would probably only complicate your current task. particularly considering the availability for chips.

aka j