Trip to the cape, am I going overboard?

[Gas_Guzzler4800]

Hey guys and sorry for another "going to the cape" thread but.....

I am planning on heading to the cape in June 2014. Giving myself plenty of time to get my truck up to scratch. I have compiled a list of "must-do's" and "if money permits" but I am wondering if I am going overboard. Some say the cape is far easier than what alot of people say it is etc. But I have always been one to over-prepare.

I will be taking the 4.8 GU patrol with an offroad camper trailer that I guess would weigh about 600kg's fully loaded. I am a little frightened of how much fuel I am going to use. Has anyone done the trip in a similar setup? We will probably head straight up the development road as I will be travelling with a 105 cruiser towing a jayco offroad camper. So we will probably avoid the OTT on the way up. But maybe set up a base camp close by and tackle the track without the campers. I have worked out that at the worst the 4.8 will use 30l/100. So 135litre fuel tank at 30l/100 gives a range of 450k's per tank. approximately 5500k's from brisbane and back will see me need 12 tanks of fuel? Does this sound about right?

Currently my truck has
3" lift
bullbar
spotties
12000lbs winch
285/75/16 KM2 mud tyres
UHF
GPS

The Must do list I have compiled is
Roof Racks
Cargo Barrier
Rear Drawers
Fridge
Dual Battery system
Rock Sliders - getting these anyway
Snorkel
Extra Spare wheel for both Patrol and Camper
spares including wheel bearings, oil, belts, hoses etc etc

The if money permits list is...
Front locker
Replace big end bearings - precautionary measure