Steve wants to know:

I am getting to the question---
I have been told by different people to use either Kwila (Moluccan
ironwood or Johnstone River teak) or Iroka for this both of which are
easily available to me in NZ and relatively cheap. I have found some
info on Kwila (http://www.dpi.qld.gov.au/hardwoodsqld/8271.html) but
cannot get anything on the properties of Iroka.

Try Iroko. Though if you're in NZ, it may not be the same, as it is African.

Charlie Self
"When we are planning for posterity, we ought to remember that virtue is not
hereditary." Thomas Paine