Firstly, Ratchet can be preordered right now at EB Games stores. You have to leave a $5 deposit. The price is $29.99 and he is dated for a September 1st release in Canada (the US will have to wait untill the holiday season).
As for the online exclusives, like Refractor, Galactic Man Shockwave and Lancer, all three can be preordered from Ages Three and Up. For Canadians unaware, they are basically the Canadian version of the typical US collectable online retailers like BBTS and TFSource. But you don't have to worry about exchange rates or customs and shipping is cheaper.
While Amazon.ca does have pages for their exclusives (G2 Sideswipe pack and Skywarp pack), they are not currently available for preorder. Amazon.ca tends to be later than Amazon.com for exclusives.
The Walmart exclusives are not on the Walmart.ca site yet and it is currently unknown if Walmart Canada will be stocking them or not (Walmart does not have a great track record for stocking exclusives in Canada).
The Target exclusives are unaccounted for, but several in the past have shown up at Toysrus stores, which is a significant retailer that usually has exclusives in Canada. The fact that these exclusives are so spread out in the US is because they do not have a big toy giant, unlike Canada. So we can expect Toysrus Canada to have some of these exclusives.
