Welcome to Oz - we did the move about 5 and a half years ago, and its been the best choice I've made (met my lovely hubby here). Altough, I have to say, I found the first year the hardest, but with so much going on you'll be fine. I found the hardest thing making friends my age, but friends who moved here with kids had no problem coz that was a link to meeting new people.

Anyway, if you're on a permanent residency visa, you'll be able to qualify for medicare, so you'll have access to the public health system. Don't know how the maternity care goes, but both my mum and a friend of ours (who were both nurses in the NHS) have been treated over here in the public hospitals and found the treatment and the service better than the NHS.
Have a good move and enjoy the sunshine!