Van as in a vehicle? If so, visit some local second-hand car yards would be the best option, otherwise online websites would be the only places I can think off.
Might be able to find the authentic van your after on www.drive.com.au or www.yellowpages.com.au... Fingers crossed you find one soon.
Hey are you thinking of painting the van with lots of hippy colours? seen some of the campervans in Tassie and they looks awesome. :)