Paul, was your dog born before or after 31 December 2010?
When did you acquire your dog, how old was he at the time?
We need to know the answers to these questions to determine exactly what you are required to do.
In general, incanton ZH all dogs whose adult size is expected to be greater than 45cm/15kg fall onto List 1 - those born after 31 December and acquired by a Swiss resident must do the ZH Welpenforderung, Junghund, and Erziehung courses. Courses must be taken at specific ages; if the dog was not a puppy when you acquired it the number of course sessions you must take in the (age appropriate) Junghund or Adult Erziehung classes increases.
If your dog was born before 31 December 2010 you are not required to do the ZH courses even though your dog is List 1.
If your dog was born after 31 Dec 2010 and you moved to Switzerland after that date you should contact the cantonal Veterinaramt to determine exactly what courses you must take. Most of the people I know in that situation have been told to take the extra Junghund/Adult (as appropriate) courses to make up the total hours - but some have not. As always, the rules are not enforced consistently. So get a ruling specific to your case.
If your dog falls into the category of List 1 dogs who are reqired to do the course you need the Adult Erziehung course, likely extra sessions. The federal SKN practical requirement will still be met within the Adult Erziehung class. http://www.veta.zh.ch/internet/gesun...usbildung.html
If your dog was born before 31 Dec 2010 you would only have to do the federal SKN theory course and the SKN practical course within 12 months from acquiring your dog.
Obviously the SKN Practical is nowheres near enough to work on the issues you describe, it's a very superficial course, better than nothing but it really only introduces you to the basics. If this is the case, I'd recommend either taking the ZH Adult Erziehungs class even if not required, or take a Familienhund class. Both will help you address your dog's behavior appropriate to his age.
My trainer is in Wollerau SZ, 15 minutes from Wädenswil. Because she is in SZ she can't do the ZH courses - but she is certified to do the federal SKN courses. So if you are not required to do the ZH courses and would rather like to try Familienhund, I recommend her highly. Jeanette Schuler-Ponte: http://www.kurse-fuer-hunde.ch/index2.html
Among ZH List 1 trainers, I have met Edith Streuli - and liked her. She sometimes partners with my trainer, but I have not worked with her. Her Hundeschule is in Langnau am Albis so not too far away from you. See the ZH certified List 1 trainer link below for her contact details, it's arranged alphabetically. You could speak with her, ask to observe a session, see if her approach is a good fit with yours.
Hopefully the Zürich contingent will be along with recommendations for their ZH List 1 trainers, Until then, here is the list of approved ZH trainers: http://www.veta.zh.ch/internet/gesun...phabetisch.pdf
Observing a class before committing to it is something you should do with all trainers. Yes, all certified trainers will work using positive reinforcement and must reject the use of pain, fear, and punishment - but there is still a wide range of practice.
By the way - is your German good enough, or do you need a trainer willing to work with an English speaker?
Here is a thread linking what I think is a clear explanation of the ZH Hundegesetz - perhaps you might find it helpful: Zürich Dog Law Explained (HuG, HuV)
A ZH certified trainer I very much respect is Martina Mettler - I worked with her for years with my deaf dog. She is pretty far away from you, though, in Weiningen. Nonetheless, here is her info: http://www.compecane.ch
Wishing you and your lovely dog all the best.