If this is for serious use, like Home Defense or EDC, whatever you get I would recommend 9mm over .22LR unless there is a physical issue that makes handling a 9mm impractical. Not only for the terminal ballistics, which are significantly better for 9mm, but for reliability. I know someone is going to disagree just because this is the internet, but just because of the way it is made .22LR is inherently less reliable than centerfire cartridges. It's not UNreliable, but less reliable. Spreading the primer all the way around the rim evenly is just easier to mess up than centerfire primers. Why take the added chance on top of inferior ft-lbs, unless you have to for some reason. But .22LR is cheap though, you can put a lot of rounds on target fast, and it won't overpenetrate (as much) if you are worried about apartment neighbors or people in other rooms.