Greyhound. Small female is 50 lbs. You would have to screen and choose appropriately to find one very interested in training, but it's not that hard. Low shed, short coat. Most bark almost never. Some are known to be "Velcro" dogs, though neither of mine are (thank goodness... I don't like "neediness" in a dog. The breed standard states the personality is "somewhat aloof". My pup is all over everyone, but Summit has a good "greyhound personality". He is friendly enough and will approach strangers if he is in the mood, but more often than not he allows people to pet him without really paying them much mind.