I have some of the choices mentioned, but for me and my wife and kids (in SoCal) I just keep the 20 guage pump action next to the bed. The kids can't rack the slide, and it has a safety. I did practice plenty at the range with it, and I would recommend you do the same. Buy the cheap 20 guage #7 when it's on sale, and fire away. You'll get the hang of it.

If you go this route, I'd strongly recommend getting a "tactical" flashlight mounted on it. It's the thing I really need, and didn't realize it at the time.

As an aside, check out the web site "the box of truth" too, for some insight into just how much drywall penetration you get with conventional pistol rounds. It's good knowledge to have.