To be honest your best bet would be to do what the rest of us Antipodeans do when it comes to razor-friendly stones: try to fluke a lucky snag in antiques stores or estate sales etc, or order from overseas and get them shipped. That's not to say you won't find anything locally, but if you are getting into restorative honing and so on it is very unlikely you'll find stones that specialised in a bricks and mortar down here.

James.