The custom barrel makers I would consider using would be SSK Industries, On Target Technologies and Match Grade Machine.
That said, I've only had one barrel made by other than Thompson/Center and I've had 30 to 40 barrels at least. The one exception has been one by SSK Industries. I've been very pleased with the factory barrels and they've cost me a lot less than those from a custom barrel maker would cost.
Since it appears you're already aflicted with the wanting-more-Encore-barrels disease, I'll give you a hint on scope mounts. If you use the Warne Weaver style scope bases and Warne's quick detach rings, you can easily switch scopes from barrel to barrel. This will save you money and room in the gun safe.
For heavy recoiling handgun cartridges, I use Leupold 2.5-8X handgun scopes with SSK Industries' 6 screw, 4 ring, T'SOB base.
