If you have any doubt, I'd call them. Some places will look up your application by VIN to be sure of the fitment. In any case if you call them and confirm before shipment you should be fine.
My recent venture was that I ordered a seat belt for my niece's Camry through parts.com (works through dealer networks) and they sent the correct part, but in the wrong color. Their little BS rule is that if you don't supply the VIN at the time of ordering they charge a 20% restocking fee and don't refund shipping, either. Since I had not supplied the VIN (though I supplied the correct color and color code) they argued with me about whether I'd have to pay a restocking fee ON TOP of paying shipping to return it. In the end they capitulated and refunded everything except shipping, but it was still a load of crap in my opinion.
In this case, though, I would confirm those part numbers through Bilstein or a reliable source. The EPC is always reliable, and that will cost you US$12 annually, but IMHO it's money well spent since you can then look up any part for your car at your leisure, at least so long as you have a Windows PC. However, those part numbers look like the ones Partstrain uses, and that's not reliable (yet another issue with that group of companies).
Thanks for all the advice! That sounds like a really rough experience, especially with something as small as a seat belt.
I have found comparable parts on Tire Rack. Though it's a bit more money (American rather than Canadian), is it more reputable than autoparts? That seems to be the general consensus. If you've had an experience with them I'd love to hear about it.
Thanks for sharing that experience, it will definitely help me in the future.