Spinoni, Bracco, or most other little heard of continental breeds. Griffons, wirehairs, shorthairs, vizslas, and the like could qualify but one would have to check pedigrees and see the parents to make a final determination. Wirehairs and especially shorthairs have had attempts to breed lines to compete against English Setters and Pointers which can make for a more hyper individual. My first two wire airs were bigger running dogs, especially my second one which would range like my trial setters. He was pretty tame in the house but he liked to reach out ther when possible.
Setters and Pointers I don't think of as being low key. The Ryman and Old Hemlock lines can be but one is more likely to find shooting dog and trial lines which can be higher strung. That is what I pick for my setters and all could be called psycho to varying degrees.
Labs from English lines seem to be the most biddable to me, friends with them seldom seem to mention barking, excitedness, or loneliness problems with their dogs. Those with American lines seem to have those issues more often. The British lines also seem to be a bit smaller if size is a consideration.
A neighbor raised, trained, and trailed hunting Cocker and Springer spaniels for decades. Of the two, the Springers seem d to have more calm individuals than the Cockers. It might be "small dog syndrome" or maybe breeding but I saw a couple hundred of each helping at trials held on his property.
In every breed there are calm dogs, psychos, and everything in between. The best one can do is research the pedigrees and trial/testing scores and observe the parents and pups several different times to see how they act. That is still no guarantee but it might help you make an informed guess. That is really what we do when we pick a pup.
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