@ 560SL
Nah, there aren't really any must-go-to Amiga places here in Sydney that I know of. Commodore Australia was over at Lane Cove (Mars Road), but they're long gone now.
The weather is always a bit crazy here, yes. Hot one minute, raining the next :-D We always get a fair bit of rain in early January/February, but then we don't get a whole lot for most of the year.
Make sure to do all the tourist-y things like go up in Centrepoint or walk the Harbour Bridge! :-)