I am reluctant to ever suggest have the barrel maker install a barrel. For them it's a production effort. All about how many they can jam on in a day. Much like a factory setting. It takes time to get the best thread fit possible and to dial in on the path of the bore rather than get close. This is based on actually being there and seeing them do it or finding it out later when there is a problem. I am just far more comfortable using a trusted smith to inspect any barrel and then put it on with pride.
The place to start is to find a trusted smith.
+1
Something to think about. First The barrel, few if any shop's that chamber and thread barrels to sell
(That don't do the complete job) use premium barrels. And if your rifle doesn't perform well, you have no recourse to get it fixed because everyone blames the other.
This doesn't mean that they cant do a good job, it's just the odds are not as good.
Most of the poor performing rifles I see fall in to these categories , Poor barrel quality, poor chambering, work charged but not done, and mainly just poor workmanship in general.
Do as Hired Gun recommended. Find a trusted and known gun smith and work with him to get what you want and expect for your money. He has a vested interested in the quality of your project and can/will be held responsible for the quality.
One other thing, even some of the better barrel makers often do poor work when they chamber and thread there barrels.
Most good Gunsmiths don't need to drum up business, but they do end up fixing pre chambered barrels quite often.
J E CUSTOM