Virgin Australia has great availability, and can easily be booked using skymiles directly from LAX/SFO. You dont need to grab them at opening date, so it should be fine for the Cali travelers.

If you are booking that far in advance, you can even find some availability from NYC, but your challenge will be getting domestic DL legs to LAX.

I ended up buying a separate ticket to LAX, and used VA from LAX - SYD - AKL and back.