I deal with both Keystone in Fort Loudon PA and Sparks in Martinsburg WVa. and highly recommend them. I know Sparks has pro-shooters on staff. I have been to but have not bought anything from either Appalachian Archery or Jefferson.
Forget about Keystone in Hagerstown, I tried to get a bow stringer for a recurve and the guy in the archery department had no idea what I was talking about.