@JLV For a good advice you should give more information about the location you are looking for. It's not the same if you live near the downtown that in the suburbs neighborhoods. At my case, (I'm a national, an argentine), my children goes to
Baica (
Baica's video here) and there are parents from Texas, and one teacher is from Austin. Others teachers are from US, Canada and even South Korea (but with Teacher Title from the US). They follow the northern calendar and also grants the American High School diploma. Tip: They are looking of teaches for the next academic year and the teacher's chidren have a huge scholarship.
It's an excellent high school for expats living in the North Corridor along the train Buenos Aires - Tigre.
This corridor has the most desiderable neighborhoods for upper middle class families with children: Belgrano, Olivos, Vicente Lopez, Accassuso, Martinez, Punta Chica, are really good places. Check it in Google maps. You have commercial zones without the smog of the City, with river activities, and with a commute time of 50 minutes of the Downtown. 50 minutes takes from Tigre to Retiro station (
https://www.trenmitre.com.ar/horarios/)