Which parks are you going to? I'm assuming this is FL - so Magic Kingdom, Epcot, Animal Kingdom, MGM?
If you are like most folks, you'll find the majority of your shots will be in the 28-105 range. On DX, that would be the old 18-70 DX, so substitute a flavor here. I rarely went past 105, there's just not a lot of shots out there (with the exception of Animal Kingdom) calling for long reach. And it usually doesn't need to be that fast, seeing that folks actually want the background in focus too, proving they were there.
Plus it's June, it's crowded and it's hot. I've only gone once in the summer, and swore never again. Something light and small. That means 18-70 (discontinued), the 18-105, replace your 18-135 with another. 16-85 is nice, but heavier. It is good to have that extra 4mm equivalent at the wide end though. 18-200 and 18-300, well, lotta moolah if you don't need the reach, but I can see it being used in other venues, so plan for the future as well as this trip.