Just a suggestion on ammo. I keep a Winchester 1300 Home Defender under my side of the bed.(My wife has my .38 Colt Det Spl on her nightstand when we go to bed.) I load my 1300 with #4 shot. At the ranges inside a house this shot size is effective . There are more pellets per round so there is more chances of hitting your target. Also, recoil will be less. Just something to consider.
I'm going to have to strongly disagree with this recommendation. There has been extensive ballistic testing on various shotgun loads and birdshot has been shown to be insufficient.
http://www.tacticalshotgun.ca/ballistics_shotgun.htmlhttp://www.tacticalshotgun.ca/content_nonsub/gelatin_testing/bird_4_rem_heavy_dove/gelatin_shot_4.html
#4 shot out of a 18 inch 12 gauge shotgun at 9 feet penetrated an average of
6.5 inches.
This is in comparison to the FBI's recommendation of
12 to 18 inches of penetration.
And this doesn't even take into account factors like clothing. A leather jacket would absorb alot of the penetration ability.
The wound from birdshot is likely to be bloody and messy, but not to be very deep. Do you want to have your life depend on a round that likely doesn't have the power to go deep enough to hit vital organs?
Unfortunately, if a round penetrates deep enough to be effective on a human, it is likely to go through a wall. TANSTAAFL
#1 shot also proved to be insufficient.
#1 shot

Measured Average Permenant Cavity Penetration: 9.0 inches (22.9 cm)
Possible options for home defence:
Lead BBs

Measured Average Permenant Cavity Penetration: 11.0 inches (27.9 cm)
Lead BBs are a definate possible home defence load. The penetration is a little short of the FBI standard, but is still likely to be sufficient and it creates a huge number of wound tracks. It is going to lose energy faster than buckshot, but at in-house ranges, that won't be a factor.
#4 buckshot is the minimum size that the website recommends for general tactical operations.
http://www.tacticalshotgun.ca/content_nonsub/gelatin_testing/buck_4_fed/gelatin_buckshot_4.html

Measured Average Permenant Cavity: 14.0 inches (35.6.8cm)
Reduced recoil 00 buck is another good option.
http://www.tacticalshotgun.ca/content_sub/gelatin_testing/buck_00_rem_tac/gelatin_buckshot_00_rem_tac.html
Measured Average Permenant Cavity Penetration: 20.5 inches (52.1cm)
My recommendations:
#3 buck if you are using a 20 gauge
BB, #4 buck, #1 buck, or reduced recoil 00 if you are using a 12 gauge.
I personally think #4 buck is the best for home defence because it maximized the number of potential wound tracks while still penetrating deep enough into the body to hit important stuff. YMMV
Buy several different loads and find one that patterns well out of your shotgun. Test it at the max range you have inside your house. Who cares if it patterns poorly at 30 yards if the longest straight distance in your house is 30 feet? When you find a load that works well with your gun, buy a case and go get familiar with it. (If you are really motivated, make your own ballistics jelly and test the terminal ballistics.)