My silgranit sink is deep (I think 9.5 or 10"), but it's no different that any other sink that is that deep. I have never had trash under the sink, but I would think you just measure from under the countertop to the floor of your cabinet and subtract the depth of the sink (you should be able to find the exact measurements on the silgranit website).

Here is my Rev-a-Shelf trash pullout under my silgranit sink. I thought we had measured to perfection but the plastic waste basket was just a tad too tall and hit the sink. Rather than buying a different wastebasket , I just cut about 1/4 to a 1/2 inch off the top of the wastebasket. Fits like a champ now!
My sink is the 1--3/4 Performa Medium. I put the pullout under the larger side. I have a garbage disposal under the smaller basin.

Here's ours, a single. We purchased the Hafele trash pullout but I didn't like and DH just made a simple base. As Badgergal says, just trim the trashcan down or find a new one.

Thank you for all the great ideas. This will give me some pictures to show the KD designer, because I have a feeling she will tell me that this idea is not possible.
Keep the ideas coming.
Thanks again
Parts