Aloha! I was in Honolulu in '98 for my honeymoon. Beautiful place.
Guns are like shoes. One size does not fit all and what is comfortable for one person is not for another. The simplest thing to tell you is get a gun that feels comfortable in your hand and that you can shoot well. Ammo for the 9mm is cheaper than .45, so that may be a consideration; you can afford to shoot more. Other than that, I say rent a bunch of guns and go with what you like.