I think this is a great thread (lets hope it does not get ruined).
NZ is very interesting as there is no particular location that can you can confidentially say "yes thats it". It also presents RL with an enormous opportunity. If for example the AFL had the footprint RL has in NZ they would be milking it for every cent. AFL will probably never have that chance so it shows how much potential growth RL can have. In fact the whole of the south pacific is RL's to grow into, sort the Origin eligibility stuff and watch Fiji, Samoa, Tonga reach their true potential. Something Union in the islands would not be able to match, anyway thats another discussion.
Now in the short run the NRL along with NZRL, ARL, Warriors etc need to sort pathways/juniors. In the long run for a Kiwi team to have a better chance for success will have to include a majority of local juniors. Not all but a majority would have to be, takes away the concern of homesick Aussie's.
Having being fortunate to have spent a wee bit of time in South island (heading back to QT in the NewYear) I can't see any potential for a team at present in Christchurch. Won't have the corporate support either and just because Union seems to be a bit on the nose does not mean they will just take up supporting RL. South island will need more time but that new stadium coming can only be a positive for RL in the long run. Few clients that I know that run pretty significant businesses in South island also share the view. The Crusaders maybe the version of Storm in NZ but they are also struggling for corporate partners etc. These guys are always getting hit up to sponsor/come to events for the Crusaders.
Both the Warriors and NZRL recommend any new team in NZ to be in a different location to the Warriors. I can see the positives of 2 teams in the biggest market. Game every week during the season at the biggest market in country. However it's the set up of Auckland that discourages a second Auckland team. League is strong in the West/South of the city. As poster mentioned earlier north shore is union heartland similar to what the north shore is here in Sydney. So a team in North harbour for me would not work. Having another team at Mt Smart would cannibalise the Warrior's support.
The safest bet at present which may not the popular bet would be Wellington. Yes it may have a smaller city population than Christchurch but this potential team will be getting most of its support initially at least from the Hutt/Porirua etc.. The surrounding area's have a bigger population (Wellington Region 527K) than Christchurch and have lots of Maoris and Polynesian's and good rail links to the cake tin. I think Chalmers in his Orca's bid had plans for a training base to be located in the Hutt.
Anyway an interesting discussion good to get the input from Kiwi's too.