Hiya Gibbles, first check import laws for Canada so you can quote the regs at the dealers, some don't want to take a risk and won't bother to check it out themselves, then go to www.kingsnake.com and check out their sellers listings, they have to have at least 60 breeders and sellers listed with the links.
By the way, welcome to MFK.
www.lllreptile.com they usually have some really decent stuff... some more rare stuff, guy I know purchased a green anaconda from them, he works with the university here though not a pet that I would recommend.