I've just phoned AA to get a quote and was pleasantly surprised. I had a little different routing: LHR-NRT-HKG-BKK// SIN-PER-ASP-CNS-SYD-WEL//AKL-LAX-SFO-LAS-ORD-YYZ-BOS,JFK-LHR and was quoted £1473 with taxes. Much better. Although the agent did say that I couldn't fly AKL-HNL even though it appears to be a valid one world flight from their web site. When I purchase my ticket I'll have to debate this with them I guess. Anyway AA seems to be the way to go.

Thanks for the advice Dave Noble.