If you are in Sydney - I'd recommend Nikon on Broadway for anything Nikon related. They do not have any online store, though they do have a website:
The guy who runs the place is very easy to deal with - and the customer service is great.
I first dealt with them to get an Nikon SB
-900 speedlight, and since that I continue to go back to them, if only for the fact I don't get the run around and that they know what they are talking about. Their prices are also very reasonable.
I don't know if there are any similar Canon minded stores.
I don't have any particular camera recommendations - except that the kind of cameras and lenses most people use do cost $$$$. How much $$$$ do you wish to spend. Keep in mind that at Sydney airport, you usually need the traditional Canon 100-400mm or Nikon "Nikkor"80-400mm VR
lens because you usually need to take long-distance photos.