The UK release isn't that bad considering what some people on here might have you believe. I've just watched it tonight and yes, there is heavy grain in parts, but there is just as many parts where the PQ is flawless. The transfer isn't perfect but overall it's pretty good. It doesn't exactly lack detail.
I'd go with the UK version unless you want to pay around £20 for the Australian disc, which is more than likely better than the UK version, if the first 2 films were anything to go by.