Relocating to Australia

Hi,
my name is kay. Im a telecoms engineer. I intend to relocate for work in australia. can someone tell me the best city to live in considering the below conditions:
1) peaceful
2) ideal to bring up children
3) cheap/moderate cost of living
4) modern and urban
5) great city all together

i would like to know the state where this city belongs like victoria or western australia etc.
thanx.