Well with a defense Budget of $1.1bn (2008) that wouldn't even get you 1xT45...
However, as an island nation... maybe just keep the Navy? Get say 4x decent air defense destroyers, stick one over Wellington and bobs your uncle...
Some Reapers and helo's manned by Naval Aviation bods - reckon Reaper could fit Sea Skua or Penguin?
Looking at the NZ Army they have nothing that couldn't be taken and inserted within a Marine Force structure...
Suggest put 'tongue in cheek' detectors on gentlemen