Been to the US several times, as others have said, the wish list is too much for even a moderately long trip, you don't want to be spending all your time either travelling or "enjoying" airports. Group the wish list by location and pick one or two focuses. Make them the highlights and just remember that the US will be there to enjoy another trip to. Also remember you'll have to haul stuff around, the more places you visit the more time spent packing/unpacking/dealing with luggage.
I am actually only back from a holiday including a 3-night stay in NYC. The hotel was in mid-town Manhattan and we lucked out with a 45th floor stunning view. It was a postage stamp of a room though. Small for one person and very small for two people and four bags (2 checked, 2 small 7kg carry-on) and at around the $300 mark per night it wasn't cheap. But that is the reality of hotels in NYC.
If you're going to more than one place or want to do/see something specific, use a travel agent, it will be less stressful and more likely to meet your expectations.
Pack very light, the old rule is half the clothes and double the money. You'll be buying stuff there, you're children will definitely be buying stuff there, leave plenty of room for new stuff.
Get the children to do some investigation themselves on how to get places, they're net-natives, so they'll probably relish the idea of doing some research online for where they want to go, what they want to do and see. Make sure they understand they have to work out how to travel from their starting point (e.g. NYC) and give them an idea as to budget. That might help them comprehend the size of the country and help focus expectations.