I think the RAM Canada computers lists in their Apple section is RAM that is only meant for particular Macs. This does not mean that RAM listed elsewhere on the site isn't Mac compatible—simply that it is not only suitable for Macs.
You are indeed looking for DDR3 PC3-8500 1066 SODIMMs, although last I checked the two brands they list (OCZ and Patriot) are currently unavailable in 2x2GB kits.
I ended up ordering mine online from OWC
. Their prices are better, although after shipping, currency conversion and duties (they're based in the US) it ended up being about the same price ($150 CAD total). Installed it earlier today without any problems.