Salsa Lessons....
I guess I can't help you, I never took lessons in Zürich or elsewhere, so I don't know who could be good or bad.
However there are many teachers and schools, you could go and check for yourself if you like the style and price of the school.
Here is a link to the salsa.ch website that has information about schools
http://salsa.ch/schools.php?idregion=ZH
I posted on the Blog my post about places to go to dance and how to learn without a teacher.