School comparison (Frankfurt)

Hello,
We are a multicultural family (French, Canadian, American, Korean, Chinese) with two adopted children living in the UK for the last 10 years.

We will move to Frankfurt next summer, and would like to have an opinion on International School for our 12 and 14 children.
FIS or ISF ?
Next question : which town to live between the "am Taunus" towns ?
Hofheim, Keilkheim, Liederbach, Bad Soden, Königstein, Kronberg ?
assuming my wife's office will be at Delkenheim and I will have to get close to the airport.
Thanks for your remarks