Getting married in the Pacific...does anyone have any tips/advice?

Hi, my partner and I are getting married next year somewhere in the Pacific. We are looking at a 'simple' beach ceremony with only closest friends and family. Our idea is ...barefoot in the sand, and just a nice get together on one of the islands, nothing too formal in other words.
Has anyone had any experience with this, and if so, what place could you recommend and how did you go about arranging this, I have heard some people just organize everything after arrival which is ideally what we would like to do, but need some 'confirmation' that this can be done without stress levels hitting the roof??
Any input will be very much appreciated!

The Cooks have a lot of weddings. Most are on the beach. If you stay at sokala Villas, Sarina can arrange the whole thing. Check out their website.