Was having a look thru NPL sides, these are the Kiwis I recognise. Maybe Wibblebutt has a better list?
Brock Messenger - Brisbane Strikers
Oliver Duncan - Brisbane Roar Youth
Emlyn Wellsmore - Brisbane Roar Youth
Zac Speedy - Gold Coast United
Michael Eagar - Port Melbourne Sharks
Jason Hicks - Bentleigh Greens
Louis Fenton - Melbourne Knights
Luka Prelevic - Pascoe Vale
Jeffrey Fleming - Avondale
Mitch Cooper - Green Gully
Andre De Jong - Hakoah Sydney City East
Mitch Cooper isn't eligible for NZ (he played for Australia U17 at 2011 WC & wasn't eligible for NZ at the time), but here's some others I know of:
Hayden McHenery - Western Pride
Shane Viitakangas - Bulleen Lions
Charlie Devereux - Adelaide United Youth
Lewis Miccio - CCM Youth
Godwin Darkwa - Sorrento
Jack Salter - Sorrento
There's probably more..
Given he has been playing in Aussie continuously since at least 2010 how could he have become eligible for NZ since that time?
http://www.theherald.com.au/story/2951709/jets-heart-goes-out-to-homeland/