Alice,
Finding a top that fits is hard I know. I have typical male shoulders, but thankfully they aren't too broad. My problem is the length. I have very long arms for a male, so finding anything long enough in a woman's top is pretty difficult.
A couple of suggestions for you is to think about tops with 3/4 sleeves. They are supposed to be short, so they look good. Another idea if you have your heart set on long sleeves, is to check out the website "Long Tall Sally." They have women's clothing specifically designed for tall women. I believe their clothes also are a little more roomy through the shoulders.
You might also try to find tunics or other tops that are supposed to be roomy by design. I actually have a couple of blouses that are supposed to be loose fitting, and because of that, they fit me really well.
Oh, by the way, I am in no way affiliated with "Long Tall Sally," the namesake is merely a coincidence.
I wish you all the best.
Hugs,
Sally