Island reggae's been bubbling since the 70's at least, like you say though the predominant style is the more easy skanking lovers sort of poppy stuff (which personally I don't mind too much, it goes well with the vibes there and just a matter of changing your ears from the "purist" setting
). Best way to check for current charting kind of music I think is to tune online to some of the local stations, say Island 98.5 in Honolulu or Q103 in Maui (you'll sometimes hear some Jamaican or international artists as well though Bob is of course the main influence, I used to see lots of Bitty McLean albums around so he has some popularity, depends on which artists from abroad sort of fit with the sound there I suppose).
If you haven't yet checked for Ooklah the Moc you need to do so forthwith, one of the most authentic roots style reggae groups to come out of Hawaii. Also the bassie from Ooklah Jah Gumby now has his own production house set up under the name Father Psalms Studio (check on Facebook and Youtube for some video content including some eye-popping clips of his massive vinyl collection!). Other than those you have some good names as far as I can tell, I might add the Black Seeds and House Of Shem (like Katchafire from NZ - quite a reggae scene there as well with which I am not too familiar), Irie Love, Inna Vision, the Lambsbread, Kohomua, Kali Navales, Ho'aikane, Mango Kingz, Bo Napoleon, Big Every Time, THC the Heartical Crew. Some of these particularly the Father Psalms crew are hitting on more of a heavier roots kind of sound so not necassarily all pop style stuff. Physical copies of much of this music can be hard to track down depending on where you will be, some only has a digital release but if you're down with the I-Tunes you should have no problems.
Enjoy Hawaii, lots of cool musical runnings and a unique and distinctly reggae friendly part of the world!