My husband bought me a desk last christmas. Since it was backordered, I coudnt open it....so he made me open other small gifts first:
Christmas Eve: I opened a small box of paper clips. Christmas Morning: I opened a package of post-it notes and a package of pens. Christmas Evening: I opened a large box that contained a small box that contained a photo of the desk he ordered me.
I have to admit, I thought he was NUTS at first (paperclips for christmas!?), and everyone who asked what he got me was equally confused. Truthfully, it was a LOT of fun and we had some good laughs about it over those 2 days!
So.... what if you bought him symbolic items? You could do things like sunscreeen, a luggage tag, a palm tree photo, sand in a jar.... and then finally give him the itinerary (be sure to wrap it!)