I think your best corse of action is to "bite the bullet" and buy an ID90 on NZ and a ZED on QF from LAX to AKL, or SFO to AKL.
Going on Atlas to SYD and then taking someone else over has a few flaws.
First of all Atlas has to stop in HNL, it's just too heavy to go from the US to SYD without a tech stop. This makes your crossing a little longer.
Atlas' airplanes fly all over the world. This makes them frequentley a late. I've jumpseated on Atlas to SYD 4 times and the best I've done is 4 hours late. I've also been on flights that were 25 hours late, one was 12 hours late, and once I got there a few hours early because a flight was delayed like 3 days so the HNL rep (great guy) called me and asked me to get on it.
Planning on their arrival times to match up with a flight across the Tasman is a way to get burned and end up spending a night in SYD.
Flights from SYD to New Zealand are very full. It would take a host of ID90s and ZEDs to assure to make it.
I'm in SYD right now and just got back from New Zealand - I bought a ticket on Expedia from SYD-NZ round trip becuase the loads were so terrible.
Just my advice.