I was shopping around for the same thing. Again, not too many options. Stockade, Sharp Shooter Supply, and Brownell's are the only places I could find ... all in the US. I remember checking out a 10BA a year or so ago at a local gun shop and it had the longer "tactical" bold knob. Looking at the Savage website it doesn't look like they come standard anymore. Maybe you could call Savage and ask. I know they ship parts to Canada.
Anyone else with some suggestions? I'm looking for a longer, thinner bolt knob that won't come so close to my scope and pinch my thumb if I'm not careful.