I don't think you need to travel to Switzerland. You can contact the head of the German SVX-Club at
schrammhn@aol.com, who lives close to you and who knows a few good Subaru garages around.
If you haven't done so far, it's maybe a good idea to become a member (not expensive).
From your description of the fault I would asssume it is either the head gaskets or a failing water pump. Both is not too difficult to diagnose - of course only, if the dealer doesn't smell the opportunity to selll a new car.
At 200,000 km you should do the big service anyhow (plugs, belts etc.) So if you combine it, the additional cost will not too bad.