Buy *A Circle Pacific ticket where you can fly to Asia via north Pacific and return by south Pacific or the other way around.

AC YYZ/YVR - NRT
NH NRT-HKG (you can add CA NRT-PEK-HKG)
SQ HKG-SIN-MEL (also can stop at Bali, Indonesia)
No *A between MEL and SYD
You can return via Air New Zealand MEL-AKL-HNL
AC HNL-YVR-YYZ

The number of stops is only limited by the terms and condition of the CP fare and the amount of time you have.

If you want to try the A380, you can fly SQ A380 SIN-SYD.