Talked to them this morning. She told me she got a fax a few days ago, but it was too small to be able to read it. Might want to try that again?
She said they've never shipped to New Zealand, so she couldn't tell me off the top of her head about shipping or legal issues regarding importing/exporting.
I don't know the laws regarding this in New Zealand, but she said you need to gather whatever kind of legal documents you may require to permit you to recieve a muzzleloader and either mail or fax this paperwork to them (it might be easier for you since the item you want is a kit, hence it is not 'shootable'). When they have that information, as well as the item (which one and how many you want), they will find out what they need to do and get back to you (be sure to give them your contact information).
They also don't do the shipping themselves, they have a guy that takes care of that for them. So when they have all your information, they will also have him figure out what the shipping will cost.
When they get back to you with all this information, then you can figure out how to get the money to them.
The item I inquired about is the one I think you were interested in, the .45 Traditions Kentucky rifle kit (pictured above in this thread), item # KR5225, $199 each (not including shipping). I told her you want three of them. She said they still have them in stock (that shouldn't be a problem as I believe Traditions still makes them; it's the CVA guns that are running out).