Garbage Disposal-Stone Sink

I'm in the process of a kitchen renovation-and I've run into a problem.
The sink is made of stone and is way to thick for the standard flange. I've looked on line and at their (In-sink-erator badger 5) brochure-but can find nothing. Any ideas? At the big box stores -the guy looks like a deer staring at headlights.
Thanks in advance-

Richard

Insinkerator does sell a flange that fits sinks up to 1 3/4 inch thick.It looks like a regular flange that they welded an extension onto.The item number is
FLGSSLG.
I doubt that you will find one locally,you will probably have to order it from an Insinkerator distributor.Or possibly they will send you one if you call them at 1-800-558-5700.Figure on it costing about 75$.

If you have a large decorative plumbing showroom in your area, they probably would have a deep ring in stock. Phone first to check stock.

Thanks-I'll be making some calls this morning.

Richard