If you want seeds of specific species roses, Sheffields Seeds in New York does sell rose seeds. I think Chiltern Seeds in the UK also has rose seeds.
If you just are interested in growing out seeds and live near Port Hope, call Pickering and see if it would be ok to harvest some open pollinated seeds from their growing fields.

Thanks very much Ann :)

I still have a few hips that have not fallen from the bushes. If you want them (and I can ship to Canada)I will be glad to sase.
Patsy