But blumming heck, you've just about covered everywhere people are suggesting, so guessing you know a fair bit on flights and that internal flights will be needed in the states, but to where will also depend on time of year especially with the little ones. Some deals do come in with flights to LA then on to other north American cities for $100 or so. if these deals were about you could look at the East coast cities Boston, New York, Washington and all the way down to Florida, from these places you have more chance to pick up good deal to get across the Atlantic, even a charter flight with the likes of Thompson. Or you could go up the west coast to Vancouver or Seattle. Last time we went to Vancouver it was actually, due to the day we needed to travel, more convenient and cheaper to fly back to LA then onto UK. Some might say this is a long way around and too much flying, to me it's a way of getting from A to E via B, C & D because that's what we want to do to see these places.
Ask away but I think you could tell us some things on travelling!