Destination wedding etiquette

Hi everyone!
My DF and I have decided to wed in Fiji in may 2014, we want to get the save the dates out as soon as possible but not sure on what to include. Do we include all travel info such as flights, accommodation and resort info with the save the date or wait until we send out the invites? The venue is after a definite number now although we don’t have to confirm until 30 days before the wedding, can I ask for a pre-RSVP with the save the dates just to get a general idea or would that be weird? 
Has anybody else that have done a destination wedding have any tips?
Thanks girls,
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