I used Mike Orlean. Mailed him a 16 gauge Remington barrel I had shortened from 28 to 26 with tubes installed (had to reset ramp and bead) and a 410 High Standard for tubes. Had both of them back in a about 10 days.
He doesn't answer emails, so if you want to talk to him you'll have to call him, but I mailed him the barrels with instructions and a check, and he did great work and had them back to me quick.
Cost me $65 to have the High Standard 410 barrel threaded for chokes, and $85 to have the Remington 16ga barrel shortened and threaded for tubes, minus the 10% SGW discount totalled out at $135 for the actual work.
Tubes could be purchased from him for $29 or elsewhere if you wish.