Here a review for Kohler faucets with all pros and cons. You can find the size also.
But the only thing I can add is that it's expensive and the problem is that some of its parts could be cheap (depends of the faucet), and might broke very soon. At least my friend had this problem and he bought...
I think it should fit. I have a Kauhler (or smthg like this) faucet with a spray head. Since I'm not a professional, it was hard to install it but manage it and it's working :D