Hi elise,
just wanted to support/ confirm gcoe's comments.
To be eligible to apply for NZ registration, you will need at least 12 months of further study or work experience (to make up for the difference in study length). That's the minimum requirement.
In Australia, anyone with a Physio degree can apply. Your application will be assessed and then you might be able to fit the criteria to sit exams - and will be able to get registered in the state in which you apply for this. There is no general "Australian" registration.

The Physio Assistant job sounds like the easy way out, however, these jobs are well sought and would require for you to show a work permit AND a medical certificate. ??? If you are awaiting an operation which requires a donor - well, for NZ you wouldn't get a certificate that confirms good health.

I would also recommend to go on with further study, or work as a research assistant.

Sorry, the news is not at all good.
Good luck!

Regards,
Fyzzio