PC12........First Officer?
CFI = Certified Flight Instructor?
You flying on an FAA certificate?
You will need to do full CASA CPL and Flight Instructor Rating, exams and flight test. See the website, the CASA website reference to converting foreign licences.
Aus is a big place, similar to Brazil in size. If your wife comes from Cairns and you can only get a job in Bunbury there could be issues.
Most Capital cities have a flying training industry, but with limited experience, and the outlook of converting licences, what Raptor said is pretty close to the mark I'd agree.
There is work here, but........
If however you have sufficient qualifications and experience and are shooting for an Australian CFI job, I.e. Chief Flying Instructor, these are about and pay fairly well considering. But you gotta put up with the whole CASA wheelbarrow of angst, and our wonderful new Part 61 debacle. If you are ME Instrument Rated and even better have tail wheel, formation, spinning and aeros training approvals you could do quite well.
Then you go work for jet star or tiger as an FO, and make a space for the next CFI
Why would you work in Brazil and marry an Australian girl??? I know guys here who would go to Brazil and fly co-pilot in a Cessna 150 just to get away from their wife.
HD