Rather than messing around with longhaul, I would take a couple of trips to NZ on LA business class to get 320 SCs. Add in some cheapy domestic (australia or NZ) flights to get the rest (or do 3 SYD-AKL round trips instead).
Alternatively, if have time to wait for a sale for AKL-CNS/PER in business (ie when QF matches NZ), then take one round trip SYD-AKL on LA and combine with AKL-CNS/PER round trip, all in business for 480 SCs.