Being that you plan to have a support vehicle, you don't really need a true "touring" bike. A real touring bike is generally heavier, often steel (most easily repaired), and has plenty of attachment points for racks and/or panniers, or the steel at least readily accepts clamps, something that a CF race wouldn't really tolerate well over the long haul. But, if you have a support vehicle, most of your gear, extra food and extra water could be in there, so there's no need to carry any more on you or the bike than the water and food you'll over the course of an hour or two.
If you were going to invest in anything, it may be new wheels, depending on what you have now. If you have some ultra-light, low-spoke-count race wheels with 700x21C tires, then you might want to get some beefier wheels with a decent spoke count (perhaps at least 32 each) and put some 700x25C tires on there that have some level of added puncture resistance. Then, don't just inflate them to the max, but choose a pressure that's commensurate with your weight.
I've not been to Australia, so I can't speak to the terrain on the eastern coast, but if there are any amount of hills, you may also want to look at what gearing you have. It's nice to have a bailout gear several days into a ride when you hit a steep hill--easier to enjoy the ride spinning up the hill than to kill yourself having to stand up and mash on a bigger gear.