I am responding with some hesitation because there must me numerous dogs out there who have and are consistently producing correct front assemblies. But, one I do know, and bred to when he first came to the States, is James ... Beechcroft Study's Top Secret. I have been in the same situation, as many of us have been ... trying to improve upright fronts/short upper arms in an otherwise nice bitch. James did a wonderful job for me, as did Ghoststone Louie Downtown in the previous generation of this bitch line. Unfortunately, neither is currently available, but the bloodlines are out there.