Shotgun aren't too great in a zombie apocalypse. You've got to pierce the brain and the tiny size of the shells and the spray of them makes it incredibly unlikely you're going to do so. I'd have an accurate, powerful rifle with silencer and scope and semi/full automatic firing options and lots of ammo instead of a shotgun. Then for my backup, I'd use either: A damn powerful handgun; desert eagle or such, a lightsaber; because they're awesome, or a Shaolin Spade. If anyone else has read the Zombie Survival Guide then they get coooookies. Oh, and an armoured car. They wouldn't be able to do a thing if you got inside it.