Don't get too caught up in the energy figures or velocity. Find something proven with a good street record, like the Speer Gold Dot or Federal HST, that shoots reliably in your firearm, and provides acceptable accuracy. The differences between most premium JHP in the same caliber, or even the difference between most defensive handgun cartridges with similar ammo, aren't big enough to be overly concerned about. It is far more important that you know your defensive ammo is reliable.
Energy and velocity are merely indicators of potential performance. How much of that potential is realized depends on how it is used, which is a matter of bullet performance. Any premium, trusted JHP on the market is going to be designed to perform at velocities typical of their calibers, so that isn't much of a factor.
And don't get too caught up in the over-penetration BS. Penetration is your friend. You need a bullet to get to and through the vitals from any shot angle regardless of whether you're shooting at a 130 pound meth addict or a 350 pound biker in leather. Frangibles and those light, fast rounds typically won't exhibit the kind of penetration you need to do this, which is why these manufactures typical boast energy figures and some sort of shock theory with very little applicability to real life.
While their criteria may differ a bit (example - FBI likes bullets that go through automobile glass), it's pretty easy to defend in court and most agencies do a decent amount of research before choosing. 
