well for you to be comfortable it will be 3 days to Cairns. Out to Dubbo, Roma, Charters towers and Cairns. Then it will depend on what you want to see. I would recommend 3 weeks from Sydney to the top and back to cairns to put swmbo back on the plane. Can be done quicker, but why travel all the way from the UK to drive past everything to see. Not only that the corrogations will kill you as I doubt you would have seen these sort of roads back home. 4 weeks would be better.
Check the Queensland reports section, as there are 3 recent Cape york trips posted by PSimpson7, Mudnut and Grizzly Adams.
Cape York by 90. June 2008
Cape York Aug 2007 Long with photo's
Cape York - August 2006 (Long, photo's incl.)
Also I have a proposed Itinerary here
http://www.aulro.com/afvb/upcoming-e...crusaders.html
Hope this helps
Enjoy
CC