Welcome Adam.
Sorry mate, I can't help with dark locations in Sydney. I left Sydney back in 1975 and I think it has changed a little bit since then
Back then we had crappy little dirty pale light-bulbs hanging under a metal cover for streetlights and the sky was still dark.
The Milky Way shone all the way across the sky.
And that was in the suburbs!
I'd say it's changed a lot since then.
Here's a pic of what we used to have (where did those days go?
)