RE: 25-06 or 6.5x55?
I would go with a .25-06 because the ammo is more available than the 6.5x55 is, at least in my area, but 6.5x55 ammo might be more common in Canada if there is more European influence in what's apopular firearm.
I think you should also consider the .303 British cal., it's pretty good from what I hear, and the ammo should be pretty common where you are, but in my area it's not uncommon, it seems people down here like sporterized Lee Enfield rifles.