LIFE is a non-profit, volunteer organization whose primary reason for existing is running monthly NRA handgun safety class for people wanting to buy a handgun in Hawaii. I was president for ... five years? I lose count. Anyway, now I am simply a volunteer instructor with the club.
I will go out on a limb and say that LIFE offers opportunities that no one else in town does when it comes to the classes. Mainly, we usually have over 40 handguns there for people to try. We follow the NRA curriculum, with the addition of an added section on Hawaii gun laws as required by HRS134. And, at least from what's published, our prices are competitive.
Now, that being said, I think that all of the gun stores in town offer their own classes. For someone who simply needs that piece of paper and has a good idea of what to look for in a gun, I'd recommend simply going with the most convenient class you can find in terms of location and schedule. Or finding an NRA instructor who will give you a 1-on-1 class.