I am originally from Bosnia and Herzegovina but now I live and work in Slovenia. I can give you more information regarding fishing in Bosnia because I did not know the rivers in Slovenia well. The only thing I can say is that the rivers in Slovenia are beautiful. Bosnia also has beautiful rivers. Slovenia and Bosnia are the best fly fishing destinations in that part of Europe.
We did have a Bosnian member posting for a while and one from Montenegro but they faded away. The images they posted were beautiful. Please post pictures when you have time, I enjoy seeing the places I may never be able to visit,