I don't know that many primary care docs or family docs know much about it, it's a little more specialized that what they usually treat.
They may know only a minor bit or incorrect info about it, and not fully understand it - that was my experiences.
Unless they are really into the whole body and muscular /skeletal conditions.

You might need to look for Osteopathic drs, physiatrist/sports /rehab types, perhaps a very good chiropractor or even a advanced PT to cover the TOS portion of symptoms.
If you can find a good family dr that will work in conjunction with the other types of care / therapy providers that should work.

There may be new TOS drs that we don't have listed yet -but this is the listing for PA from 2006

you should be able to call/contact them for some referrals or other names.

Pennsylvania

Dr. Robert Young Rhee / Asst. Professor of Surgery
Presbyterian University Hospital
Pittsburgh, PA.
(412) 383 - 7074
E-mail: rhee@pittsurg.nb.upmc.edu

Dr. Allen Togut
166 Hanover St. Wilkes-Barre, Pa 18702
Phone: (570)824-2500
E-mail: ajtogut@epix.net
fax: (570)824-7910

Dr N. Gupta
UPMC Bower Hill Rd
Pittsburgh, PA 15228
Phone: (412)648-4000