I'd go with the 3913 9mm as a great conceal carry. It's durable and hasn't failed me yet. Although when I was a poor recruit all I could afford was a model 64 2" .38 special which many of my compadres laughed about until we went to the range and many couldn't qualify with the glocks they all...
940 j frame
I'd buy it. It's a good price for any Smith & Wesson revolver not to mention its a J frame and a 9mm. I wish I could find one. I would carry that off duty without a doubt.
Hawaii State Police
Your are correct there is not state police in Hawaii at least like most other states have. There is the Hawaii Sheriff's which are for the entire state. They are pretty limited though to state properties (Roal Palace), courts, and the airports. They do some of the traffic...