I can only think of one and i'm not 100% I know it as the Rossignol shop underneath the Ela hotel opposite the main entrance to the Samokov hotel. The guy there is called Lubo i recall. You might be better off getting them done in the UK. In my opinion.
Agree with EMJAY, shop under Ela Hotel. But again I had custom fitted boots back home heat fitted etc time taken 1.5-2 hrs. feel like slippers. They come with me as well. (Slippers)
Well I went to Ellis Brigham in the Milton Keynes snowdome and bought a new pair of boots. They charged me £65 for the fitted footbeds and they had to stretch one of the boots too. That was 2012.
This is compared to the £300 odd it cost me to have orthotics made by the podiatrist.
Therefore I consider £65 to be good value