I can strongly recommend Don Willams from the Actionworks in AZ. Not much of a website, but he is an Hi Power expert. He did beautiful job on mine. New Novak cut for sights, stipple and refinish. Flawless outcome on a pistol with huge sentimental value.
http://www.theactionworks.com/gallery.htmIf you want local I would try Paul Grundhauser.
http://grundhausergunworks.comPaul is very talented and does a lot of work with local USPSA competitors pistols. He would certainly be able to do a very nice trigger job. He builds awesome open guns.