I can't speak with any authority, but I was just searching for the same information for the same reasons (replacing PS hoses). The one fluid I saw recommended most often was Valvoline Power Steering Fluid, though there was no shortage of other suggestions; that's what I decided to go with. No idea about availability in Oz, however.
As to the hoses, before you start trying to seal high pressure hoses with band clamps, I suggest you check availability for the proper replacements. I found all three for a combined total of just over $40US. The fittings are a pain to get loose, but at least you know you'll have a decent seal. I'd be very leery of a band clamp holding up under that kind of pressure.