On my last trip to Christchurch in 2009, I found the place in Papanui to have ceased offering E6 processing; as a result, all my work had to be taken through umpteen X-Rays (which I hate doing) for the return trip home. Post-earthquake, I don't think that store exists now. Surely there are other E6 photographers around New Zealand; I can think of semi-regular APUG posters that come to mind? Your best option might be to mail over E6 jobbing to Melbourne or Sydney. It will be an exercise in patience and trust, but if E6 really does end in New Zealand, you've got to think outside the square, taking it wherever and whenever it is still available. Could be quite costly with postage, but you must exhaust all options before throwing in the towel.