[Dana]

You can request a car seat from Tiffany's when booking your reservation. I don't think you need a car seat on the airplane for your two year old, but check when you book your trip to be sure. I know I didn't use one when my daughter was three, but cannot remember if you need one a two or not.

With all of the extra things you have to bring, I would just rent a double stroller from WDW for hte girls. You older one is definately going to need it too. You only have to rent one once a day even if you "hop" parks. Just keep your receipt and show it to the next park. You get a Disney dollar for returning them, but I'm not certain on the prices of the doubles. My DD is 9 nad I can't remember how much the singles cost me, but she used one up until she was six. It's easier to keep track of them in the parks and it gives their poor little legs a break from all of that walking.