Damn economy of scale! I curse it everytime I go out and buy mascara! I miss Canada sometimes
Canada/US is only 120V which is basically half of what NZ uses and their plugs are not slanted. I successfully use some of my electonics with just a plug converter as they are within the range of 100-240V...laptop, battery charger, curling iron, etc... I imagine an Aquaclear filter would be ok (you can check if it has that range online), I used to have one in Canada but I don't remember what the powerhead said. Anything that is not within range, you can use a power converter...although at this point, I don't know whether its worth the hassle. The only thing I've had a problem with is clocks not working because of the difference in Hz. Even though its says it can do 50-60 HZ, the time ticks by quicker!
I think that if u hunt on Ebay.com and Ebay.ca, you will come across a seller who can do shipping reasonably and will send here.