Chris, I am far and away from being a gun expert (I only have one firearm), but if you are worried about a 12 gauge shotgun being too powerful for you to handle, you could look in to either low-recoil ammunition (it does make a big difference) or a 20 gauge shotgun. At close ranges a 20 gauge is still more than enough (way more than enough) to incapacitate someone at short ranges, and the recoil is lighter. We almost went with this, but my wife has been able to handle the 12 gauge, so we are happy with that. If you go to a firearm store (we used Bass Pro in Rancho) the sales people ought to be knowledgable and will hook you up with exactly what you need.
Wrongone2messwith, I am not worried about an intruder wrestling my shotgun from me. This brings up the question of tactics. I'm not going to be walking through my house with shotgun in hand searching for the intruder. So I won't present the opportunity for him to take my firearm. I will be in a room behind a closed door. If that door opens...then I will use the shotgun. Some might want to take more offense-oriented, pro-active tactics, but unless you have military or police training I'm not sure that it is wise for home defense. If you hear an intruder, call the police, and only use the gun if and when directly confronted. That's my philosophy, although I know others may disagree.
Incidentally, I would be a bit less confident in using a hand gun. The first thing to go in a high-stress situation is your fine motor skills - unless you are firing that handgun regularly at a range, and have committed that skill to second-nature muscle memory, you aren't going to fire all that accurately. One still must be proficient when using a shotgun, but accuracy is not nearly as critical, and I'd be a lot more confident that I could use it effectively even when panicked.
