I was just mulling this over while having my breakfast out on the balcony, I think a trip like this is kind of like buying a boat, you need to truthfully decide what you want to do, no use buying a caravan with multi wheels, shower, toilet and air cond, if you intend doing the full off road thing, or, only have a small tow vehicle, there is a hell of a lot to months away from home. As an example, my brother has been retired for quite a while, and has probably seen more of Australia than most, he has had camper trailers, poptop vans, motor home, big vans and tents, nothing is perfect, he now has a huge van with everything in it, he tows that to a major town, leaves it in a nice van park to use as a kind of base to do camping trips around the area, right now this seems to suit him (probably not me though) remember everything is a compromise, even a rooftop boat has some valuable tips I can give anyone that I have learned the hard way, put simply, you cant have everything, you can't tow a 16' boat and a caravan, a car top boat is also a compromise, it's never ending, think long and hard about it, listen to everyone's thoughts and sift out what suits you.