I guess I will jump in here and offer my opinion.
I would say a set of bolt internals (Extractor,extractor spring and plunger, firing pin and ejector and spring) ,a spare op rod spring USGI if you can find it ,a hammer pin, trigger pin and a hammer spring . A combo comes in handy too and a 30.06 empty case to assemble your bolt if the need should arise .
Good thing for you is almost all of the parts mentioned are also M1 Garand parts, and I understand that you have access to M1 parts there in Canada.
The only parts that will not interchange with the M1 are the: firing pin,ejector and spring,and op rod spring and of course the combo tool .
If you just want the short list get the bolt internals and the spent case as a minimum.
Hope this helps
Mike