In Australia people travel with *far* less carry on bags than common practice in USA. Very common for people to check bags.
With QF all tickets include a checked bag allowance. With VA check the ticket t&c's
Do you really need that much checked luggage for your trip?

Check-in is self service at most airports. For both airlines they generally do not measure bags. But can. And if the carryon bags "look" heavy or very oversize they will/may ask you to check in. If in doubt check-in bags.


VA
https://www.virginaustralia.com/au/e...ry-on-baggage/
https://www.virginaustralia.com/au/e...ecked-baggage/

QF
https://www.qantas.com/au/en/travel-...n-baggage.html
https://www.qantas.com/au/en/travel-...d-baggage.html
With QF can have 14kg max carry on, with the heaviest no more than 10kg (so 10 + 4 kg)

Other airlines in AU are JQ Jetstar, REX and Bonza (new airline). But REX does not fly your routes

Enjoy AU & NZ
Note both countries require visas and both are *very* strict on food / wood / plant material importation.