For use around the house "until you can get to your shotgun" implies you are going to keep it with you. That means either literally carrying it around and setting it on the counter by you (something I do) or finding one small enough and light enough that you can "super carry" - have it in a holster on your person even in the home. Yes, my Glock is on the desk as I type this. If I'm in the kitchen doing dishes it is on the counter next to me. In the shower (sorry for that mental image!) it is by the bathroom sink. I literally pick up or put down the weapon dozens of times a day. It spends a lot of time in my hand. I like this because it feels very, very familiar now. I know what it feels like loaded and unloaded. I routinely slip my trigger finger up and check the loaded chamber indicator, etc. I believe it is a good way to get, and stay, very familiar with your firearm.
Where was I? Other considerations. Think about environmental issues - darkness. You might want night sights on whatever you choose. You might want to purchase a small, reasonable flashlight to keep with it. Something like a Maglite XL200 won't break the bank, are a good size for one handed use. Use common batteries, and offer plenty of light for indoor situations.
Whatever you choose make sure it is fun to shoot. You should practice with it as much as possible. That means something that does *not* have punishing recoil. That means something that takes ammo you can afford to fire off 100 rounds or so each trip to the range.
If you use both "range ammo" and "self defense" ammo - make sure you fire off several boxes of the self defense ammo too. You want to make sure there are no issues with your firearm and that ammo. (more of an issue with semi-automatics) You also want to know if there is a significant difference in recoil. (goes for your shotgun too)
Have a plan. Consider where you typically spend time in your home. Kitchen, family room, bedroom. Consider likely scenarios where you might want your firearm. Intruder breaks in front door, sliding door, window. Or forces their way in when you answer the door. Will you need to confront the intruder or can you retreat? Can you take up a defensive position and wait for help, or must you go on the offensive and clear the room/house? Practice moving around you house in the dark, weapon in hand. Look for light sources (windows, digital clocks, etc) where you or an intruder might be silhouetted...
In selecting a caliber and ammunition consider number of rounds you might have to fire. How many might you need? What about rounds that miss? Will they penetrate walls?
In short, there are lots of variables and every person's situation and priorities are different. Hence there is no one right choice. In fact, there are probably many choices that are for all intents and purposes equally good. Have fun, think it through, then practice practice practice...
Very well thought out post. thank you.
Excellent post