For those not quite thinking like parents:

First off, most of the smaller cities that have direct service to the US on CO or US are operated with 757s, meaning the seating is 3-3 and less than desirable for a family in Y; if in C, then 2-2 is fine.

My second thought is that if travelling business with kids, then an old-shape business cabin will suit better (ie US, CO etc - not NZ) because the seats are beside each other and not in a herring bone configuration. (You don't want a 4 yr old unbuckling at the moment of take off).

Third, forget the trip to DUB to save on APD - adding 5 hours to a journey to save even £360 is just not worth it when kids are involved.

Next, depending on the age of the kids, I'd try to avoid the west coast due to the length of the journey. If they have no concept of time, no problem. If they can watch a film, eat ice cream and then watch another film, with gameboy here and there, no problem. However, if they have a concept of time, but no concept of patience (ie 4-7) stick to the east coast (probably Orlando at a guess).

Orlando is a good spot for heat, kids and redemption availability on LH. Taxes will be high, though, compared with some of the American airlines or even NZ. (You could trade this off against a trip to DUB (just to contradict myself )). I did DUB-EWR-MCO with a 3 and a 1 yr old recently and, despite, irrops (delays, snowstorms, missed connections) it was quite manageable and no one melted down (honest!). Another plus for DUB is that you can pre-clear immigration there, rather than queueing for 30 mins-3hrs at the other end.