How can you possibly choose between secret technology you do not know
I do not even have the hull form of said ships, i take it that the technical systems and electronics can be chosen from different producers and may well double the initial price.
What is the draft of those subs, speed, maximum diving depth etc., no real knowledge about different aip systems, is Kockum's better than the german one, how easy to maintain and refill, what about electronic warfare units and so on.
How are the canadian preferences, what is mandatory for them and so on.. so no
real idea.
England does not build conventional subs, not even for export, but sells all kinds of systems for those.
The spanish Isaac Peral (S-81) maybe a bit too big (again don't know what Canada needs or prefers), but not yet established in a way all problems have been sorted out. The bioethanol fuel cell AIP is quite a good idea though, and maybe less prone to problems or accidents.
I take it the Kilo is beyond question just out of national preferences, though it is quite good and established, and could be fitted with any AIP system.
My guess would be the swedish or the german one then.
If Canada decides to go for nuclear propulsion (and some say it will), this will be an entirely different question..