Last year I had a great experience with Smith-Worthington saddlery (based in Hartford CT). They have detailed instructions about how to do a wither tracing on their website, and they will make recommendations about what saddles to try that are likely to fit. (They are exclusively representing their own saddles, though; but they do have several different models).
They’ll send trial saddles or, since you’re pretty close, you could actually go and pick them up, which is what I did. Before you take the saddle on trial, they’ll check to see if it will fit according to your tracings. You can then ride in the trial saddles for a couple of weeks, and if you like one, they’ll fine tune the fitting.
It was a really good experience.
http://www.smithworthington.com/index.php?p=catalog&parent=1&pg=1