As long as you can get your opponent to stand still right in front of you, squared away with a frontal shot, at 10 feet (like a block of ballistic gel), you're good to go.
If he's farther away, or is wearing heavy clothing, or you have to shoot through his arm or shoulder, and maybe he has a backpack slung over that shoulder (or all of the above), then you have some variables and may need a little better performance.
Hey, it's your call. I'm not trying to talk you into anything. Anything you choose is the right answer, for you. What I'm trying to illustrate is the constant "this is the right answer, and if you choose something else, you're wrong."
These are living creatures we're talking about shooting. In some cases hollow points will perform better, in other's, a ball round or semi-wadcutter may perform better. You could make the "right" choice in gun or ammo, and it could be the "wrong" choice. On the other hand, a .380 with ball ammo is a lot better than a pencil, unless you're John Wick, of course.
The other point is this constant fear of over-penetration. There just isn't any evidence of this being an issue. Missing your intended target, sure, but most self defense gun uses are not in crowed areas, and even if they weren't, handgun rounds, especially non-magnum rounds just don't penetrate that much.
If I told you on Monday, at 10:00AM, at 5th and Main Street, you were going to be in a gunfight. There is no getting out of it, but you can bring any gun you want, and you don't have to conceal it. Would you bring your .380 with 80gr hollow points to ensure you don't have a shoot through and dump all the energy into your opponent, or would you bring your AR-10 with 30 round mags and 165gr .308 rounds that would probably shoot through three people and waste all kinds of energy down range? I'm guessing most people would choose the AR-10 and take their chances they won't hit somebody else because the .308 performs a whole lot better than a .380, in most instances.