S.K.
These are all great! Just one more thing to add: squeezable apple sauce! You can get a big box at costco or the regular grocery store also carry it. It's great because it doesn't spill and you can recap it if they don't finish.
Have a great trip and don't forget the DVD player. It's a long trip with litlle guys. Also you might consider bringing the portable kids potty so you can pull over where ever you are! Especially since you are making a point to eat fiber. I promise you will be glad you did! Have a great trip!