Hi Michael,
One question - why do you want to go the the US so badly? I played to a relatively high amateur level here in Australia before briefly turning pro and experienced some excellent programs right here in Australia - through state junior golf, state golf, National programs and the VIS.
Many firends of mine went to the States through the college program but from my experience few offered comparable programs and unless you were one of the star players you ddn't necessarily get to travel to all the major events.
Given your age I wouldn't have thought you need to rush into anything. I would be aiming to make your state junior side first off and if you play well enough, perhaps the National junior team awaits. As soon as you start making these sides and sqauds you will find doors quickly open up - national events, international events etc.
Even if you stayed here after school, if you can make the senior state team the same thing applies - national squds, national teams, overseas represntation, VIS / NSWIS / AIS, funded trips etc etc.
Whilst America sounds fantastic there are some benfits in being in a 'small pond' so to speak.
Best of luck with it all,
Mike Cocking.
BTW - Irrespective of which option you choose finishing year 12 is about the best advice anyone could give you - especially if you are a little unsure what you want to do. I did an engineering degree at University before getting into the VIS and then finally getting into golf course design and I was constantly amazed at how many 15, 16, 17, 18 year olds I came across were prepared to give up school because they wanted to be a golf pro. In fact every year at the Australian amateur I bet most of the field (180 or so) would have answered with a big YES to that question, yet if lucky 2 of them would make a great career of it, perhaps just 1.