In a home defense situation against a hostage taker, I think my first choice would be a 12 guage slug. I think the slugs will offer better terminal ballistics after penetrating intermediate cover such as wives or children (luckily both of which are replacable... and luckier still, I have neither so I can get away with classifying them as expendable and not having to sleep on the couch
).
In all seriousness, however, I think you're on the right track with the handgun for interior defense. A shotgun or rifle (or both!
) make a good addition to the bedroom, though, incase you need to barricade yourself in there and wait for help.