One must choose between a large capacity magazine.....a 9mm auto holds usually 17 rounds and the reliability of a revolver.
Ruger makes a great revolver in the SP101.....in .32 H&R and .357 Mag. S&W also make superb revolvers!
Load the .357 with .38 specials for a easy to handle and easy recoil gun.
Either choice requires a lot of practice and familiarization with the firearm and a committment to "shoot to kill" should one ever have to use it!
A lot easier said than done