He has a pleasant head and nice set of ears. His neck does not say saddlebred or walker to me but possibly a cross. He's not at all hackney. I would rather see the whole body and legs squared up or stretched. He has high withers and a slender barrel. To me that would mostly eliminate quarter horse. My guess, without seeing a whole picture of this pretty fellow, is that he is thoroughbred or standardbred - though he's lighter boned than a standardbred - possibly a cross. You say he's really pleasant. Then that's the best of all worlds. Enjoy him and he'll be an amazing friend.