Thanks for the reply Damar.Hi Emmis,
To begin with your last concern. I would consider a year of getting up-to-speed with the other children, learn the language, make some friends and getting used to their new environments. Don't see it as a lost year but rather an investment in their future study results and social skills. So what if they fall behind the first year, as long as they are happy and motivated to catch up later on i would not worry to much.
And if you didn't like the first "nieuwkomers groep" school, try to find a better one. It sound obvious and it actually is . I assume they can provide you with all information at the "Gemeentehuis Amsterdam".
Of course it's obvious... but thanks for pointing it out! We have checked out both the integration groups that we know of in Amsterdam, as well as one in Haarlem, and they are all really intimidating! But you're right - it makes sense in the long term.
I'm going to do some more research and find out if the two groups that primary schools constantly tell me to go to, are really the only two in Amsterdam!