For a drop-in sink, rent a grinder with a diamond blade and make the cutout what you want. If one grinds and one holds the Shop Vac, the dust isn't too bad if you open the doors and windows.

Thanks! I was having the same thoughts. Seems like it would be easier to do that than search for a sink with such a specific cut out

Build.com has a decent search tool that will let you narrow your search by size. Might be worth the fifteen minutes to see if they have an undermount that will work. Undermounts are a lot nicer, IMO. You may need to go with a single basin, which I also prefer--as do many here on the kitchen forum.

Good luck!

Have you double checked the front-to-back distance of the countertops you bought? I would double check this to make sure they will fit your base cabinets in your kitchen. The reason I ask is that it sounds like the sink the size you need might be more of a bathroom vanity sink size? If these are bathroom vanity marble slabs they may only be 21 inch, and your kitchen cabinets might need 24 inch slabs.

Exactly what I was thinking . Sounds like a vanity slab.