Nathaniel:
If you have a Michaels craft store near you they stock it there. Here in Ontario its in with the Pastes and Polish section. I am sure you should be able to locate it there.
I have in the past rented a U.S. post office box across the border to receive kits and items that can not be shipped internationally. If this is not in the budget have a group of friends go in on it. Or find some hobby shops in the U.S. and do a road trip.
Cheers;
Gregory