I had a quick chat with one of the instructors at Bankstown who pretty much indicated that an incomplete EASA training cannot be counted towards CASA training. You would need to start from the beginning.
However if you complete the EASA PPL in the UK before you come to OZ then you can easily convert it to a CASA PPL. Just a couple of exams, couple of hours in the air and a medical.
Sydney Aviators (part of Basair) and Sydney Flying Club seem like good schools with plenty of aircraft and availability.