There is an industrial Singer that is 12"--can't think which one it is now that some folks have turned into a quilting machine and the Bailey as previously mentioned comes in a 13" version.
New to the market recently are some 11" machines: the Janome Horizon and it's cousin the Elna 7300. I believe the Husky/Viking Sapphire 850? is also. And Bernina has a large version out now but I don't remember how large other than the large price tag--LOL.