I highly enjoyed the cruise my husband and I took in the French Polynesia. Being on a cruise ship affords a bit more flexibility (different foods and activities for everyone's taste), and lets you see more places.
I do not know what dates the cruise I went on would be available, but I do remember that there were sporatic dates (and a mixture of different destinations) available throughout the year.
To give you an idea of MY trip, since that's the only thing I can comment on specifically:
The cruise started in Tahiti, and lasted for 10 days. We started in Papeete, where I did a 4x4 expedition into the mountains and played in the waterfalls.
Then went to Huahine where we did the island tour, saw the Vanilla Plantations (Tahitian Vanilla is their biggest export, and the orchids are stunning), and played (literally got in the water and played) with the island's sacred blue-eyed eels. They're tame, and swim right up to you... and it's the only place in the world that has blue eyed eels!
Then we went to Rarotonga, which is actually in the Cook Islands and spent the day on Muri Beach.
Then we went to Raiatea and took a day-trip to Tahaa (which is, btw, the MOST GORGEOUS PLACE EVAH). We went drift snorkeling there, where the current pushes you through the coral reef. It was the best snorkeling I have ever done in my life, and we go someplace EVERY year. The highlight was then watching the sun set over Bora Bora in the distance.
From there we went to Bora Bora for two days, and went scuba diving, then stopped off in Moorea for a day and did I THINK the ancient ruins? I know we did that somewhere but I can't remember where....
And then finally ended up back in Tahiti. That day we went to the other side of the island and visited the black sand beaches, and Teahupo'o (pronounced Cho poo) which is one of the largest (and deadliest) surfing waves/locations in the world.*
*We did not surf!!! Haha
We used Princess Cruise Lines because of the dates/locations available at the time (we wanted to go specifically at the end of September). But there were other cruise ships available. Regent is another one that comes to mind.
Good luck picking a location!