The QF awards are quite difficult to get if you are not using QF miles. IMHO, the best option to Australia in F or J would be the CX award from AA. Cathay has one of the best first class products out there, and will make the entire trip better, especially if you have never flown international F before.

The only possible downside is the mandatory stop in HKG. I view this as a plus, and would spend a few days there also.