First, forget about the big hardware stores and go to a plumbing supply store like Hajoca or Noland. They may not be prepared to sell directly to you, as they do wholesale only, but all you need to do is find a friend who has a contractor's licence who will get it for you. Look at BAR sinks primarily.
I'd look at Simonhanbury's pictures too - he did a great renovation and I think I noticed he had a small rectangular sink that was deeper at one end than the other. (I thought it would be perfect to wash a baby in.)