I see that you are in South Australia, If you want to have a great experience you should do a Perth to Adelaide or Adelaide to Perth Tour. It is a very unknown part of Australia but it is such a beautiful place to see and so much to do. you can swim with sealions and dolphins or a cage dive with the great white shark. very special. you should check it out. about 6 years ago
I agree with Craig that the West is lovely, however if you want to check out the East coast of Australia, with only 8-10 days, you're probably best to head across and see a bit of Victoria, then head up the coast to Sydney.
It's a long way to the Gold Coast, so unless you like driving a lot (and not seeing or doing much else), then you may want to spend more time in a few places and get stuck into some of the amazing experiences like surfing on one of New South Wale's beaches (take a look at Surfcamp.com.au) or diving or dolphin watching in Jervis Bay. Then you'll have some time to spend in Sydney too. about 6 years ago