I'd suggest contacting your local exotic stone slab yards. The best ones should have sources all over the world and many can do special orders. Just make sure you understand that limestone may be more porous and sensitive to chemicals than granite or marble. If you plan a hard-working kitchen where tomatoes, citrus, olive oil, and spices are common it might not be the most practical choice. Quartz products are not the same as natural stone but the latest man made surfaces do not have pixelization or repetition like early versions. I'd definitely compare with a man-made quartz that looks like limestone before buying.

Thank you for the suggestions and information.