ULES
The first would be to investigate cadetships with QF etc. IF you fit the bill for one of those you coud save yourself a few steps on the ladder and possibly a bit of money. If you have to do the course you've mentioned you have to take the traditional "baby steps" . By the sound of it you may finish this course with a bare commercial and command instrument rating. You next have to build experience on multi engine to make yourself more palatable to the majors. This experience can be built up doing charter work or freight but you have tos tart off on singles and more than likely "go-bush".
Instructing is another way to go but the multi time probably won't come as fast . One thing that will put the brakes on is a lack of year 12 English, and even if that is not a requirement, spell-check all your correspondence! Also ATPL subjects are a must and I would recommend getting these out of the way while you are in the studying frame of mind and still close to good training resources just in case you do have to do some remote work later. Also, keep in mind that even if you don't eventually make it into the majors(and many don't) there are still many satisfying(if not as financially rewarding) jobs in the industry. Good luck with it.