Jace.. Of coz Orlando. Been there (although without the small one) - We had jetlag, a little tired, but manageable. Ashley (5 years old then), would wake up at 3 am feeling hungry and afterwards couldn't sleep, so I had no choice and not sleep too. Not sure for little kids as I have yet to bring Emma that far.
If you're going to disney world, there are like 5 places to go: Magic kingdom, MGM studios, Epcot Centre, Animal kingdom and downtown disney (this is just shopping). You can also go to kennedy space centre, univ studios, seaworld and legoland.
I stayed in NY for a few days before flying to orlando, so by the time we're at the resort, the jetlag was gone.
Another good thing to go to US: factory outlet!
PB
Emma went to the dentist at National Dental Centre, after a recommendation from KK hospital, so she has subsidized rate. Cost us $30 for check up plus cleaning. They have kids room decorated with stickers, glasses and of coz stickers for the kids. When Ashley was younger I brought her to GPA dental (either at Parkview/United square) - Dr. Ong Teng sin or Dr. Chong Chian Ee. Dr Chong is especially good with girls, she is super gentle. However, it is expensive.