Hey, what about building the steirische Ostbahn from Graz to Fehring or Szentgotthard? The db br 642 with a new ÖBB livery would perfectly fine and if you also add the ÖBB 2016 for freight services this would be perfect. I think this would not be too much work because it is quite linear. Greetings from Austria!
If somebody has time and a lot of info I can suggest the Mariazellerbahn but before the "himmelstreppe". I cannot stand those trains
