To my fellow NZ anons,here are the pros and cons of ordering from each of the available online stores. I've shopped from all of them, and gotten consistent results.
nzgameshop: Cheap price (Usually between $20-$30 cheaper), but shipping time is AWFUL. Don't expect to be playing XY until about the 22nd at the earliest.
EB Games: Their prices are high. However, their preordered games are released a day early (Which means we may have a 2 day headstart on everyone else)
MightyApe: A fairly decent price, and consistent shipping time. If XY come out on either the 12th or 13th, expect your copy to arrive on the Friday - they ship preorders to arrive as close to the date as possible, but BEFORE the release date.
The other thing to keep in mind is that it's usually EB Games who get the decent preorder bonuses, but it's best to wait and see on that one.