Caveat: I don't have cats, nor do I know much about them.
So why am I posting here?
The company that makes my mutt's favorite food (Terra Canis) also makes a premium cat food, Terra Faelis: http://www.terrafaelis.de/index.php
This is a small company in Bayern, DE that ticks my canine 'must haves': Lebensmittel quality, named meat source and parts (venison muscle and heart, for instance, instead of just the name of the animal), a grain free line, ethical production, etc.
A quick look shows that Taurine is indeed added to the cat food.
Terra Faelis can be bought here in Switzerland at Meiko or Zooplus (both .ch and .de)
I'm quite a fan of the dog food so I'm tossing out the cat food info, in case you might want to look into it. But as per the caveat above, I don't know much about kitties.
Another premium cat food possibility is Gina and Fritz, a small Swiss manufacturer. Looks like they do not add Taurine, though. http://www.gina-und-fritz.ch/ch_ch/o...enfutter.html/
Wishing you and the kittens all the best...