Hi.... let me give you a thought. I totally recommend the International Arboretum of William (Bill) Valavanis. P.O. Box 23894
Rochester, NY 14692-3894 Tel: (585 334-2595).
Of what I can tell you are about 250-275 miles from him. I am about 300. Each year I have ordered bare root imports. I pay for them in Nov/Dec (I think) and they arrive in April. He will mail them, not sure about shipping to Canada, but I pick them up. You should check with your authorities about importing from the US. If you can you should think about either A) the bare root imports or B)a trip to his facility to purchase established trees. I can not say enough good things about Bill. He is an extremely well respected Artist and a really nice guy!!
http://www.internationalbonsai.com/arboretum/ARB.html this is a page of his web site. there will be a sale on Sept 8 at his place... no mail order. It is in conjuntion with INTERNATIONAL BONSAI 2002 SYMPOSIUM DECIDUOUS BONSAI II . If you can make it you will not be disappointed!