Some stainless ideas:

Elkay ELU2317EK
Franke CQX11024
Franke GNX11028 (actually 28.75 overall length)

Check with your cabinet guy instead of your granite guy...if they cut down the sides of the cabinet base far enough to accomodate the sink, you'll probably be fine. The big thing is making sure the basin part will fit within the overall width of the cabinet (outside edge to outside edge) & it sounds like it will. We were in the same boat...our cabinet base is 36" and the sink measures 37" overall. When I asked our cabinet guy why the spec sheet said the cabinet had to be 39" or greater and he was saying he could make it work, his response was that you just have to deal with someone who knows what they're doing. When the time came for the install, the base cabinet sides were cut down in the shape of the sink basin using the actual sink as the template. The granite was slid into place and the sink was secured to the granite. No problem. Good luck & stick to your guns--if that's your only sink, you need as much space as you can get!

I too would recommend notching the cabinet sides. The bowl fits in the cabinet, the top installers just need room to get their clips/ wood blocking in to support the sink.

Undermount SS blanco 441024. No need to cut cabinet.

I just had this same concern with a Kohler Lakefield (33" x 22" overall undermount size) fitting into a 33 inch cabinet. I was thinking that they must make them for these cabinet sizes as this is a stock size and so many of the Kohler cast irons seem to to be 33 x 22. I was told by the seller that they need 1 1/2 inches of space on each side of the cabinet for the undermount. Because our countertop and cabinets continue on each side running on top of the dishwasher to one side and the trash compactor to the other there is plenty of room even though it is a 33 inch cabinet..The interior of the cabinet sides do not run all the way up to the countertop so there is that space for it to rest on. Did some measurements myself and my old sink is the same size so I went ahead and bought it ~fingers crossed. I did make sure I could return it.

Yes, the Blanco that debrak posted is better (bigger bowl) than any that I posted. 26" interior would be just fine, IMHO.

Thanks for your input: Angie, the CQX11024 would fit but the back of the sink
is only 9" wide. The Elkay is better w/inner bowl of 23"wide and the Frankie gnx11028 will still be too big per the granite fabricator.

Mydreamhome: Thanks, my next step was to call the cabinet maker and ask him about it. The fabricator uses pieces of granite, instead of clips, which they glue. They told me its stronger. Its frustrating b/c if we had the sink we would have the granite installed next week!! Now I have to find a sink that works and don't want to have to sacrifice the size and still prefer the under mount!
UGH!!