The bullbar AND driving lights will come in handy in the outback. Try LED lights rather than halogen or HID. ARB's deluxe bar is what I should have ordered with mine, I guess that'll be on the next one.
UHF radio, portable fridge, perhaps an aux battery system to power that fridge, maybe an awning - for outback trips we added a long range tank because we were refuelling at Marla in SA and had to drop another 40 litres in (from jerry cans) at the SA/NT border rest area so we could comfortably make it to the Shell at Erldunda.
Don't forget roo whistles. They don't scare the roos off - roos are too bloody stupid - but they do scare dogs, sheep, goats, rabbits and cows. Bloody roos all race on to the road to find out what the hell is making the noise!