I'd really like to see one of the Melbourne Metro lines in TSW2 - particularly the 11-mile long Sandringham line as I am very familiar with it, maybe plus the City Loop. However, one of the longer lines might make more sense from a sales standpoint. As for locos, perhaps either the Siemens Nexas or Comeng plus the new HCMT for some variety.
I like the idea for a route like this, however: Waaayyy too short for a full on route, even the longer routes in Melbourne are less than 40km, why not stretch the boat out and have Metro and V/line services on the Geelong line? Sales would be higher for a Sydney route (speaking fairly objectively) as it is more famous and probably more interesting with double deck rolling stock and cool infrastructure (not to say Melbourne has no cool infrastructure; it does, especially the new grade separation work areas!). Metro Trains is part MTR run, MTR is part Chinese owned, Chinese Government not too keen on selling their brands. This is probably the reason why Rivet's island line will go unlicensed, as the 30% MTR stake in SWR is enough to let them control brand decisions. Keep thinking of good ideas though, its nice to see the forums more populated with an international audience.
Excellent suggestion. I've suggested this before. This is one of the routes I wanna see come to TSW2 most. I know Metro Melbourne REALLY well and am growing up with it. They will very much be my childhood really soon.