I just wanted to second SolarityBengals comment on sedatives sometimes not working for kitties. The 1st time I flew with my babies, the vet prescribed acepromazine & Pete Pete had a TERRIBLE reaction to it. Not only did it NOT sedate her, it made her MORE nervous & high strung. If you are certain that you want to use a sedative, make sure the vet gives you enough so you can test it out a few days before you leave. That way you'll know what kind of a reaction your baby will have.
My kitties never want water when they travel, but just in case I usually bring a bottle of spring water & a small water dish so that I can offer them some throughout the trip. They also travel in a Sherpa, which they seem to find quite comfortable. I usually leave the Sherpa out for a week or so prior to travel & put treats inside it at least once a day so that they come to view the Sherpa as an inviting place where good things happen; this cuts down on trauma when they have to get in it for the trip.