Can't get Insurance for a round OZ trip

I challenge ANYONE, especialy David & Michelle, to find an insurance company that will cover our 4wd, Caravan and personal effects while traveling OZ for an extened period (2 years +) both on and off road. From what I have found, unless you have a permanent address - which most dont on these extened trips - your stuffed. No-one will cover you. One option I have been suggested is to use someone else's address as your own - like relatives or friends - but is this legal? Surely there is something available to us. TCIS are useless unless you are only going for a short period.