Just let us know how you feel once you've had to return a couple loaded calipers that were incorrect. Where the parts guys give you AD18's instead of AD22's. I wouldn't pull my car part, and walk to the store expecting to get the correct parts - get the correct parts and then pull your car apart.
I view this along the same lines as AutoZone and Advanced's "lifetime warranty" on parts. Their computer systems clear your history after 1 or 2 years, so you have to make sure and keep your receipt (that typically fades) so you can exchange your brake pads, calipers, etc at a later date. They can keep other info for years without an issue, but my warranty history has to be purged. I might be rationalizing, but the times I've had to buy stuff a 2nd time makes up for the time I screwed them on a core exchange.
You might want to place your order for calipers and verify they are available. Just b/c they are listed doesn't mean they can actually still get them. There might not be any rebuilt AD22's available anymore.....you know, with cores not being returned.
A little tech for this thread: buy a 10mm flared wrench when you do the brakes especially if you are replacing the brake lines. Don't try to use a standard open ended wrench. Craftsman should have a flared wrench with 10mm on one end and 12mm on the other. Have that in your collection.