Hi there
I did the same in 2007. See
Claudio Angelini.
My advice would be to take your own bike.
This way you can test your set up back home and everything is ready once you get there. In my opinion it's cheaper anyway and you know what you have. Looking around for some bikes in Down Under I figured they are quite prizy and most of them come with lots of miles on the clock.
Once you get there, organize an Aussie Sim Card (is sometimes even required when applying for a job or for the tax file number) and open a bank account in one of the big Aussie Banks. This will give you a local debit card and therefore less costs when paying for fuel and other stuff. And you don't need to carry lots of cash, since nearly everyone accepts them.
Keep in mind that Australia is expensive, even more when you head for the Outback. Fuel was then at 2 A$ in the Outback. Food doesn't come any cheaper. I would even say that prices are comparable with Switzerland.
Therefore forget about fruit picking. You earn f.. all and work long hours in the sun. I managed to work as a mechanic in some places and the paid up to 36 A$ an hour. Some mining companies offered me even 60 A$ as a diesel fitter if i'd stay for 3 months!
One piece of advice; yes, you can extend you stay in Australia for another year on a working holiday visa but only if you have done 3 months in a agricultural business... but keep in mind, you could also do the same in New Zealand. They have the same deal as Australia. So in total could cruise around for up to 4 years on those islands! Keeping in mind that you have to enter any of these countries before you turn 31.
If you have any questions, don't hesitate to contact me. I did 55'000 Km in Australia on my Africa Twin and worked for about 4 months in different places.
After that headed North via East Timor to Indonesia and the some other countries of South East Asia. They are dead cheap and I was living of my money I earned in Australia for quite some while.
Greets from Kinshasa
Claudio