Whilst this kind of tour is not my "thing", if you are too busy to arrange your own trips, and would like your kids to get the most out of the expo experience, you could take a look at some of the tours available through travel agents. I just happened to come across this tour, being run through Lion Travel. At between $5,000 and $6,500 per person for two days and one night, it's not that "cheap", but you do get to stay in a nice hotel and enjoy a lot of different activities.
If you are looking for this kind of tour, you could also contact hotels to see what they are offering. My friends sometimes take part in tours run by the Brother Hotel.