What are you looking to get done? There are some folks who do rifles, some pistols, some both.
My first recommendation is Neil Keller in Decatur - Kustom Ballistics
There is also Verne Trester (sp?) here in Indianapolis, but I'm not familiar with his work. Gary Growe is down in Columbus. I know Marc Brock has done some gun plumbing in the past, but I'm not sure about right now?