NZ is the strongest carrier for the Pacific Islands I have found and very helpful towards staff.
I've used them to the Cook Islands twice.
Other than price, air services are limited so you may want to factor that in.

NZ flights to NAN are via AKL.

Another option is HNL - NAN on FJ.

I think if you try QF via Australia, it's a considerably longer flight, dpending on what your ZED level is with QF vs NZ, if they are matched, it will be
more expensive on a longer flight = more miles.

Good luck !