Air passes around the South Pacific?

Hi,

I want to go to several islands in the South Pacific in May-July next year and am trying to find out more about international air passes in the region, especially something called the "Visit South Pacific Pass" - it is mentioned in books but I don't know how to book it.

It seems to be a sector based, priced in US dollars (bummer, given the pound is so low at the mo) and covers the more obscure destinations like the Solomons that others, eg. the Air New Zealand pass, do not.

My ideal itinerary would be:

New Zealand - Vanuatu - Solomon Islands - Fiji - Tonga - New Zealand.

I already have an Air New Zealand return flight London - NZ - London because I am working for a few months in New Zealand beforehand, leaving Dec 15th 2008.

Specific questions looking for answers are:

Does anyone know of any good agencies in the UK or NZ for this sort of independent travel/flights?
Has anyone bought the 'Visit South Pacific Pass' recently?
Does anyone know of any other passes or deals or ways to do this?

Thanks!

Amanda