Thanks all.
It will be economy flights as they will be for personal reasons. So we will be paying for and choosing the USA - Aust flights. And will probably be able to do so 4 - 6 months in advance
Internal flights within the US will also be economy as far as i know. And my work does not have any prefferential airline or gain any discounts. We just book the flights ourself (within a budget) and they reimburse us.
Sounding like AA is our best bet?