I just completed a move less than 3 weeks ago...
We simply tried to keep things as 'normal' as possible, inspite of boxes and such. Made sure to maintain play time, and lovin' on everyone like we normally would. Ours took it all instride, actually...they actually enjoyed playing in the boxes that weren't put together yet!Lol! And not to mention the newspapers we had collected for our breakables...those were scattered all over the place each morning, and whenever we came home from somewhere!Lol!
I kept all their toys out until the last minute, and when we were ready to hit the road, I put the two that didn't like traveling, in their kennel together, and the one who could careless, in hers. I wanted them in the kennels for as short as possible, so they wouldn't have to use the potty box along the way, even though I had it in an accessible place in the car. I didn't feed them the night before, and picked up their water in the morning before we were going to leave.
I make sure cats have a cozy kennel; too large, and most will freak out cause you lose the 'cave' feel-they like being cozy; although, a large one can come in handy for longer trips, when you need to put a box in there. But I have found that a smaller kennel with super cozy blankets, and a buddy (if they don't like traveling) helps a ton even with the most nervous kitty! I never use medication.
If you can, take them on some shorter trips before you leave, so you can figure out how they will be on the trip. With just two kitties, I would think they would probably travel better in one kennel, that way they can cozy up together...and won't be so scared.