1. Malaysian Airlines. 5* airline with 34" legroom. You will have a stop in Kuala Lumpur. Some people recommend Emirates though you would then have 2 stops.

2. Virgin Blue or Jet Star, you can also fly with Quantas but their flights are usually more expensive.

3. I paid around £875 when I flew with Malaysia two years ago. You can probably get cheaper flights but not as much legroom.

hi Parky
In Australia we have three carriers 2 no frills and Qantas that give you a meal Virgin and Jetstar you have buy your snack meal to get prices of all flights at differant times try
http://www.travelthere.com
They all differ at times of day and days

Go to the websites of the internal carriers in Australia. We had an email just yesterday from one of them offering 1 flight at full price and the next one for 3 dollars. Last year we booked quite a few BOGOFree with Virgin by booking them from UK before we went (when they advertised the offers) Just went to the websites every week.