Sounds good Swiss. Aussie's an awesome place. Too bad we don't have onca around anymore...he could tell you about it. Nationality matters a little bit. I dunno about the situation in Australia, but in the USA, you have an advantage if you are Hispanic not necessarily Spanish. This is because Hispanics are largely underepresented in US private colleges. Need to research more on Australian schools before I give you a definite answer on that one.
Anyhow, good luck with everything. Remember that no matter how well you learn the techniques Kaplan teaches you, it's all worthless without practice. Practice makes perfect.
If you really want to do well on the test, I would do at least 8-10 tests before you take the exam. Also remember that you should not take the SATs more than three times, but the colleges typically take the best scores from all the tests and combine them.
I don't know about SAT Subject Tests and Australian schools, but they might require those as well.