Hi Adam
There are very few places within 25k of the Sydney CBD where skies are even dark enough to see stars of the 4th magnitude let alone the milkyway. However the ASNSW has a site on Bowen mountain "Crago". with an observatory and 16" telescope. This is about half an hours drive from my place in Kellyville.
We go there once a month on the weekend during the new moon period.
The site is quite high in the lower blue mountains but it is often crystal clear when Sydney is overcast. It is possible to see the milky way from horizon to horizon and the large and small Magellenic clouds.
We would love to have you join the ASNSW but you can also come to Crago as a visitor on the viewing nights. For the dates see the ASNSW web site
www.asnsw.com
Barry