Hi, don't know how much this will help but here goes anyway.
We are going to Adelaide on a state sponsored visa - it's a three year temporary visa. We could have opted to get a permanent visa for Tasmania - that would have been state sponsored too, but permanent. We chose to go to Adelaide because it seems more like where we want to be - we're not living in a big city at the moment, so won't miss any bright lights Adelaide may (or may not be!) lacking. Like you say the temporary bit of it is a bit scary, but my guess is that if you're able to support yourselves once you're there they have no reason not to let you have a permanent visa. You can apply for this once you've been living there for two years and working there for 1 year.
We've done the TRA bit, the State Sponsorship bit and have now sent off for our visa, so are settling down for the long wait.
Have a look on www.domain.com.au for examples of houses being sold now/available to rent to see what kinds of prices you would be looking at.
Best of luck with your research.
Wendy