Would it really be a good idea to play one team twice 3-4 days apart? If you were going to bring them down for two games it would make more sense to play a NZ selection, maybe even All Whites, for the Auckland game. That way you keep it different and fresh for the public.
Keep it fresh? Well it sounds like the games will be in different cities, so you'd pretty much have an entirely different crowd at each game.
But for the second game you watched the first one on TV. And there is a danger that West Ham wins the first one comfortably. I think seeing the contrast between the Phoenix and the All Whites would be quite fascinating and a prospect that just isn't possible except under (these) rare circumstances. Bringing in NZF would also help share the costs and bring in all their sponsors.