From my time up North on the mines I've learnt a few things that all serious bush basher 4wd's should have..
1. Long range tanks - for when you get lost as there is a looooong time between fuel stops sometimes. That 400km wrong turn sucks when you know you have to backtrack.
2. Room for at least two spare tyres, if not more - you won't get a flat on the road, but on the rocky/gravel tracks you will as the sharp rocks will slash the sidewalls.
3. Room for plenty of water - nuff said.
4. The usual recovery gear - which AHG should outline for you. With this - a front mounted winch might be a bit extreme pricewise, so maybe a hand winch or something cheaper like it. Either way, not a bad idea if going it alone.
As for driving, revs, momentum ect - it depends on the terrain and where you are.
Think about weight, weight distribution ect when looking at a vehicle. You don't want to be doing 5000km+ in something that's massively overloaded for it's chassis/engine. Also, the more you put on a roof rack, the higher your center of gravity will be and in a 4wd, it's already up there...
That's all I can think of for now..