Try streetracerparts.com. (Las Vegas, Nevada-USA)
Here's why. Right now they make the indiglo's with MPH on the outside and KPH on this inside.
But they do take requests. If you can get a total of 10 people that will sign up to purchase, they will make a gauge for ya.
Email them first, tell them you want a ZX-6r gauge indiglo in KPH and tell them you'll round up 9 other buyers. I know we got some guys on here in Canada (KPH) that would like indiglo's in KPH also as well as you guys "down under" so I'd think that rounding up 10 buyers won't be that tough.
Main page:
http://www.streetracerparts.com
Requests Page:
http://www.streetracerparts.com/model_development.htm
Contact Page: (Has 800#, but old address)
http://www.streetracerparts.com/contact_us.htm
If S.R.P. gets enough people wanting those KPH gauges, they'll make them. Also it would have to be 10 of one kind. Either 10 of the standard indiglo, or 10 of the reverse indiglo.
Good luck,
-Flash