There are 3 grammar schools on the North Shore district, Sea Cliff, Glen Head, and Glenwood Landing.
All three are located in residential blocks with lovely property, playing fields, and playgrounds. These 3 grammar school fold into the 1 middle school grades 6-8, and the high school is 9-12.
I have 3 children myself who all attended the North Shore Schools and went on to good colleges and pending careers. You can call me if you want more info.
As for Catholic Schools, we have All Saints Regional in our area. This is for K-8. This past week they had an open house, however, I'm sure they will show you around any time if you are interested.