I must agree with Mr Bikenut. He has given good insight and sound wisdom. I also carry at all times, regardless of whatever else I am carrying, A Kel-Tec P32. As already stated, not the best, but better than nothing. I carry mine with the first two rounds being Speer Gold dot hollow points. These wont penetrate very deeply but when a bullet stops inside the target, 100% of the energy has been transferred to that target causing as much initial shock as possible. I then follow up with ball ammo for penetration and deep organ damage. Of course I have never had to prove this in practical terms, thank God, but it sure sounds good in theory, dont it?
Back to your original question, of course as has already been pointed out, the .32 mag is the more powerful and potentially lethal round, but the choices of small, easily concealed weapons is very limited.