Magna-port international. Big shop, fast service, good prices and excellent results. But, you have to mail it off to Mt. Clemens, MI. I would check the local guy first, but if he doesn't have what you need, check out Magna-Port.
I work part time for Scotts. He isn't a specialist. He does a little of general gunsmithing including a fair amount of machining. However, he could handle pretty much anything S&W you throw at him unless you want blueing. He usually subs that out.