I hate to be the one to rain on your parade, but your strategy to fly business class this way will not be successful.

1. There is no way you will be able to earn (by flying) or buy 125,000 miles between now and November, and even if you could buy the miles, it would be very expensive.

2. Even if 1 somehow did work, there is no guarantee that there will be business class seats available to redeem (how many is we?). November is a very popular time for NZ/AUS, and I'm pretty sure that you'll have missed the boat if you did get the miles.

If you want to fly business class, you should check with various websites. My guess is that the fare will be something like €3,500 per person in November.