Relocating to Sydney

My husband's company is posting him to Sydney for 5 years and we are in the midst of collating useful information on our relocation. Our main concerns are that we have 2 children age 7 and 11 and was wondering if it would be better for our older son to finish his PSLE exams in Singapore before we move over. Would there be anyone who could offer advise on where is a good place to stay which is not too high end and which schools are good for our children to adapt to? I'd really appreciate information on anything that are useful to us since this is the first time we are moving to Sydney.

Many thanks.
SKTan