We booked our hotel+air package with sunquest 14months before our wedding to secure the rates for 24 guests. I'm super happy we did now, because with the price of fuel going up the prices have gone up too, but we're locked into our price. You have to check with your TA, one of the issues with us was that Sunquest only had a certain amount of rooms at the resort that we wanted, so we didn't want to wait and risk there not being enough for our family. They won't be able to guarantee you the exact flight time or date, but they'll be locked into a price, and the tentative dates. Its a bit nerve wracking (at least for me) not knowing when I'll be flying out exactly but oh well.