I can't tell you the spec. of the cameras BUT I do know if you buy a grey import camera you can not get a Panasonic warranty, some retailers offer there own limited warrenty but that may be very limited. One of my cameras turned out to be a grey import so I know first hand. I thought I'd found an on-line bargain from a UK seller but then when it was delivered and I registered the camera with Panasonic, the serial numbers showed it was from Eastern Europe. I got no support or warranty. As it turned out I didn't need any as the camera has been fully and perfectly functioning for years.
This is the gamble when you buy a grey import. Should anything go wrong with the camera within a short period you should still have your statutory rights (what ever they are in Australia). BUT after that you will have to find a reliable camera repair man should anything go wrong with it. I would give it a really good shakedown, testing all the functions etc. If it's all ok, then cross your fingers.
Being more optimistic, these days cameras seem to be very reliable, until the planned obsolescence kicks in.