In Murfreesboro -
http://www.bamcustoms.com/
Seen good things about this guy on TNGunowners.com -
brandon@midtngunsmithing.com
Old Hickory Gunsmithing in Soddy Daisy gets good recommendations.
Personally I would have it Cerakoted or Parkerized for a more durable finish. Hydro dipping will rub off if it is a holstered gun.