The difference between a Commander and a Government doesn't really affect the fit of any of the parts you're looking at changing. Your best bet with any 1911 is to have the parts fitted by a pistol smith. There is no guarantee that any 1911 part will drop in without some fitting - in the case of safeties, this is vital. As suggested above, Brownells ships to Canada, just keep your order total under $100 per order, and you're golden. Most folks like Wilson parts, and no gunsmith will refuse to fit them (gunsmiths hate low quality parts, and the good ones will refuse to use them).