We (me, the bf and two gay friends) have done a few South Pacific trips. On one trip we stayed at the Meridien Ile des Pins in New Caledonia for a full week. We were four gay men in a hotel full of honeymoon couples (mainly Japanese) and were made to feel hugely welcome by everyone. We even got a special surprise breakfast on the beach on our last morning which was fun and wildy camp.

On another trip we stayed on Vahine Island in French Polynesia and again were very warmly welcomed and had a cracking time. We went on to Bora Bora (aka boring boring) on the same trip and had no issues at all but it (Bora Bora) was pretty dull.

Tonga was another fun and memorable trip (the same four guys again) and no-one gave us any hassle although we were a little lower key on that trip

Generally I think you'd have a pretty decent time anywhere in the south pacific so i would focus first and foremost on where you want to go and then choose the optimal lodging choice on the island(s) that you've chosen.
But you'll have fun wherever you choose

cheers

Fritz