The only language everyone needs to worry about is the English language, which is the language it was made in. I think it is a disgrace and an utter lack of respect to the actors that motion pictures and TV series are still being dubbed. Just watch it in English... you can post here in English, so I have no doubt you can understand the English language. As far as subtitles go, I can understand that this may be important. Check the Amazon review for a detailed list.
Hi Montauban: Your posting is more than just a little bit arrogant. To write a question in a "not your own language" is often not so difficult, than to understand a complete TV-Series. This could be hard work and no fun - and looking TV should be fun. In fact, I think that AMAZON.UK is full of people like you. This could be the reason, why there are no information about the languages.
English is not the only language in the universe. Be honest: Did you read Shakespeare in the klingon original?
I checked season 10, there's only english audio available. It seems, somewhere between season 4 and 10 they stopped adding non-english audio streams. Maybe I'll complete the language details in the next days/weeks.