The K&N would probably be your best bet I would say. They are not only the leaders in their field but they offer a one million kilometer warranty in most cases. It might only be 500000, can't remember. I would have no doubt that the HKS one was developed in Japan and would probably not be entirely suited to our climate, especially Broome of all places. How is it over there at this time of year by the way? Hot enough for ya?.
Would only buy the unifilter if I absolutely could not afford the K&N. They do make good filters though.
The short of it is this.
You can pay $150 for the K&N and never look after it and never clean it and it will be crap.
Any air filter has to be maintained and cleaned, these all can be cleaned, I guess it comes down to your budget in the end.