Just replying to the message above, Modelcrafts and Hobbies down in Wellington have the odd ACE kit, but their website http://modelcraftsandhobbies.co.nz only lists one. You could still try them.
One of the better overseas sellers of ACE stuff is www.hobbyterra.com, a Ukraine based retailer who offer reasonable prices and reasonable plus fast shipping (i.e. US$13 for 3-4 kits). I've used them twice now with no problems at all. Aviapress.com is another good one, though a lot more expensive per item (over twice hobbyterra) they have a fixed overseas postage rate of US$15.00. I haven't used them yet though.