As for for pounds of energy, it depends on full metal jacket, semi jacketed, semi jacketed hollow point, flat nosed full jacket, flat nosed lead, all lead round, all lead, conical, etc. My two personal favorites, are Federal's Hydrashock, and PMC's starfire, which is basically a Korean version of the Winchester black talon. Speer's Gold Dot is another good one. You want to keep in mind what kind of clothing it has to go through, before hitting flesh and bone. As for velocity, in either configuration, in a 115 grain bullet, you are looking at around 1100 fps +. Plus P a bit more. Most police dept.s that still use the nine mm, are using a 124 grain bullet. The 115 just wasn't putting the bad guys down with one round. Most have now gone over to .40 cal. I still like the .45 cal. I still like the 1911 style, and I have a few of those, and one is a S&W double action which I really like. I would love to have a Para Ordinance, with the double stack clip, but Can't afford it now. In the nine mm's that I have, when I carry one, I have it loaded with Hydra Shocks, or PMC's starfire. The .45 the same. The Glock is a fine gun, it is just not my personal choice. I just feel more comfortable with a 1911 configuration. I originally did not like the 1911, and preferred my S&W revolvers. Then I shot a friends .45. I liked it, and have been a fan since. It's like cars and trucks. Whatever is reliable,fits your wallet, and comfort zone.
The Glock has an outstanding reputation for reliability, and that alone is a good thing to keep in mind. After that it all comes down to what you personally feel comfortable with, as for grip, balance, style,cal. etc. If you are a Glock fan, more power to you. I can't stand Blue Cheese, or butter milk,
but the world is full of people that absolutely love that stuff.
Wayne
