There are not many on the site who live out in the burbs. If this is a corporate move or you can otherwise afford it, I highly recommend you work with a good relocation specialist. Zona Norte is sprawling and there are a lot of considerations from whether you want to be near the train, be able to walk to stores and restaurants, want to avoid the hordes of mosquitoes near the water......
Another big issue for many expats, including me, was the thought of driving, or especially an older child driving in BA, so that could really impact location. We tried San Isidro, it was pretty, and cooler in the summer, but we couldn't leave fast enough. There is so little outside of country club life which you'd need good Spanish and good connections for.
There are plenty of spots in CF where you can get the house, backyard and pool and still
have the amenities that are what make BA to me. Lincoln has buses to pick up kids from all over. I'd consider Belgrano R, not to far from the school, Houses, yards and so close to the fun of the city.