If all else fails, try mixing your own. I made up a batch for this year's work and it turned out fine. I never thought I would be doing this, but it was very easy and much cheaper once you have the scales and raw chemicals. There is really very little you need to know in order to do this type of combination. Some distilled water, a couple of beakers, chemicals and a scale are all it takes.
I know you can buy from Artcraft or Photographer's Formulary in the U.S. but I don't know about shipping to OZ. You might try them with an email and see where you end up. They are both knowledgeable and decent to deal with. If you decide to do it this way, remember that PMK keeps well, so order enough to see you through for a while. Remember to use distilled water for your working solution, as water quality varies considerably and times will as well if you don't use distilled. Best of luck.