Then I'd again recommend the 870, couch. AR-15 is unforgiving to bring into action in a half-awake state, pump is easier.
Also, make sure your cell phone always works, and a ham radio to supplement it might not be stupid.
Also, have a plan for door knocks. Remember that you can manipulate a shotgun and you can manipulate a door, but you can't do both at the same time. And do you have any way of seeing who's at the door without them seeing you? A good security/surveillance system can come in very handy, particularly if it can reliably (cell, not landline) inform you when you are away from home that somebody's waiting for you inside.
As a temporary measure, you can maybe leave a visible tell, but, like a leaf above the door that falls when it's opened, but most idiots will see and replace that one.
Make sure you have a good relationship with your neighbors. Offer them brownies or cookies and give them your phone number.