I agree with Mince, doing the road trip will be far more valuable in the end. If you do it right you can go see a lot more operators along the way as well. When you get to Darwin you'll probably want to make trips to both Katherine and Jabiru as well to see the operators there so once again a vehicle will be essential for that.
Plus when you get that first job you'll want your car there as well, you'll get called up at odd hours to go do a quick charter or scenic flight and for the operators it is a BIG tick in the box knowing that you are available and able to get to the airport quickly. You really won't be making quite enough money to be taking Taxis to work everyday when you do find that first job and you can forget about public transportation for that sort of thing in Darwin!!
Other than that you seem to be on the right track, you're a little bit outside of the normal hiring season so perhaps even taking just a month or so to do some additional research and get some extra funds before leaving wouldn't hurt and will make life a lot easier in the long run.