LA will not make more than 1 seat available AKL-SYD in A except maybe on the day of the flight (they only have 5 seats in F and reserve it for SCL-SYD traffic). Presumably there are 2 (or more) of you traveling, so you may have to use QF for AKL-SYD (the 6 am flights include 763 and 744 equipment, but it doesn't really matter for such a short flight).