Keep an eye on the 4-sales on the Club Veedub Sydney website,
http://www.clubvw.org.au/, or subscribe to the magazine and get it fresh in your letterbox each month. Kombis come up for sale almost every month. There are also 4-sales in the VW Australia magazine, but that only comes out every couple of months. Otherwise look at the car classifieds at
http://carsguide.news.com.au/ and similar.
'Bay Window' Kombis are fantastic (I have one myself) but something a bit more modern might be better if you require reliable transportation for your youngster. Have a look at T4 Kombis (ie after 1992) - they are bigger and more comfortable than early Kombis, with modern Golf-style mechanicals. And they are still Volkswagens. Lots of them around, too.