clon: are you actually looking to register a .au or .nz domain, or a more international domain (.com / .net etc.)?
I don't know about the .au or .nz domains, but I use GoDaddy for my .com domains and haven't had any problems with them (touch wood!). If you want to use GoDaddy, don't forget to use the coupon code 'saveten' to get another 10% off. Plus, if you register more than three domains at the same time, you can get free private registration...
Mata: I don't know of any market for phone numbers but could set one up if you need it
Alternatively, just put it in the paper alongside the custom licence plates!