Good on ya! Confidence in your equipment goes a long way with your ability to defend yourself. A lot of people will deny it but the emotional connection to their gun, ammo choice, etc affects their ability to be proficient with their firearm. If you "feel" you're going to miss your intended target, it becomes a self fulfilling prophecy and you'll subconsciously make it happen. The same is true for feeling you are going to hit your target too, of course. If people didn't use their emotions to pick equipment, we wouldn't see nearly as many 1911's being used as defensive weapons. They're hardly the most size or weight efficient, are low capacity by modern standards, and the uber tight race guns and uber cheap knock offs are not known for reliability. But they make their users feel confident in their ability to protect themselves or loved ones and that's what matters.
People virtually never pick a gun based solely on an objective analytical comparison of the gun's features and benefits. I'm certainly that way. I picked my carry gun because it made me feel protected by what I saw as the best weapon available.
If 124 grain rounds are the ones you feel will serve you best, then they will. Don't worry about the mythical "stopping power", just place your shots where they need to be and fire until the threat stops.
Bobby