The only new things we've really seen the New Zealand military get over recent years is some new fancy SAR kit which lead to the military trying to by equipment by focusing on its rescue potentials in times of disaster but that obviously does not include submarines, tanks and fighters. The more likely stuff they will try and use that reasoning for Air Force wise is a potential P-3 replacement that could be needed within the next decade (depending on upgrades), the regional transports and maybe a couple more A109s which I heard they might be getting.
Regionally this is the sort of kit they would need as well as one of the big issues affecting many countries such as Tuvalu is the drinking water shortage and disasters caused by rising sea levels and recent weather patterns (la nina) such as Tsunamis, floods etc.
Like I've already said a lot of it comes down to cost and capability. NZ doesn't have the capability to run a sub force. Look at issues Australia is having. As far as tanks or MBTs go, we have long gone past the point where we can sustain such a force. I've already covered the ACF issue. This has been done to death.
Let me put some things into perspective for you. NZ has the same population as Sydney. We have a rather low population density with high deprivation and poverty amongst the population. Some numbers. Some 20% of kiwi kids don't get enough to eat every day. We are not blessed with the large mineral resources that you in Australia have. Depending upon which sets of data you use somewhere between 30% and 40% of the population live either on the poverty line or below it. In Maori and Pacific Island populations the figures are far higher. wages in NZ are 25% lower than in Australia but the basics like food are similar. If you look at the official figures for the median wage or the average wage it takes into account the income of professionals such as lawyers, judges, politicians etc. Not just blue collar workers, so it is artificially high and does not reflect what in excess of 50% of the work force actually earn. Kiwis struggle to survive. As a general rule unlike Australia we cannot afford to have a life style. That explains why a lot of kiwis cross the ditch.
The old days of the 1950s and 1960s when we could afford to have MBTs, a cruiser plus 4 - 6 frigates, a bomber squadron and a fighter squadron are long gone. In 1984 this country was broke with the highest debt level in the western world. Now we have to live with what we can and can't afford and whilst there are some of us who would like to have more capability it aint gonna happen because when you have a lot of hungry kids what is more important?
So lets be a little realistic and then you have a look at what the NZDF actually do with what they have.