hey mate,
sounds like you have a good attitude so aussies will welcome you im sure. The schooling/university system is a bit different to over there I think u might have to look into it a bit further but it should be ok.
Sounds like Brisbane may be ur choice place close to east coast places, I guess as others have said cost are lower in Brisbane, Perth etc but they have lower population and therefore less jobs and lower pay compared to Sydney or Melbourne. Thats a general statement however, just depends what ur after they are all good places
good luck
ps - for day to day surfing Sydney is arguably better than Brissy, closer beaches correct me if im wrong, but they are close north and south of the harbour, beaut harbour too :wassup: hotter up north though better for small trips