As mentioned, it is strongly recommended (would like to say mandatory) that you have good All Terrain Tyres in a Light Truck construction for this trip.
There are some sections that are the nice smooth bitumen, however other places are very corrugated, and a bit of sand and everything else chucked in as well.
When moving from bitumen to the dirt / corrugations it is recommended that tyre pressures be reduced, then of course pumped back up when back on the bitumen. This not only gives you a comfier ride, but also protects your tyres from staking (puncturing). It also looks after your vehicle as it won't be bouncing all over the place due to high tyre pressures.
There is a good guide as to what pressures are suitable for which terrain that would be a good idea to download and take with you here:
http://cooper.etd.07.com.au/media/1400/cooper-drivers-guide-tyre-pressures.pdf Also to be able to pump your tyres up again it is recommended that you have an air compressor of some sort (and two hoses so you can pump up your camper tyres too as these should be let down at the same time as your 4wd tyres). So you know how far to pump them up to - you'll need a reliable tyre gauge.
So in short: LT Tyres, Compressor, and Tyre Gauge.