Some things to keep in mind:
Two of the most effective pistol rounds in history - the 125 gr .357 and the 115 gr +P+ 9mm JHP - penetrated less than 12" and "will get you killed" according to this study. Often, the bullet missed large, blood bearing organs, yet stopped the BG.
There's been a lot of jealously expressed by the authors toward those who are more concerned with how ammo works in actual gunfights (the guys who’ve gotten the most press and written the most books and articles).
This type of study led to the adoption of the badly designed subsonic 147 gr 9mm JHP by the FBI and many other agencies. Penetration was there (when the cop didn't have to shoot through anything to get to the BG), but the low-energy bullet did a poor job of saving the cop's life. New, higher velocity 147 gr ammo is much better, BTW.
Nowadays, any premium JHP ammo in any reasonable caliber will do just fine. Nobody is making bad defensive ammo. Even Winchester "White box" JHPs are better than most "high performance" ammo made when this study was written.
Personally, I carry a Glock 19 loaded with Federal 9BPLE 115 +p+. An oldie, but a VERY goodie!