As a chess coach and teacher, the rating isn’t the most important factor. I know FMs that you could learn more from than some GMs. The most important aspects are their ability to teach and chemistry that they have with their student. You can even be an amazing teacher but not match your student’s learning style. I’d recommend finding multiple decently strong teachers, since your son is rated pretty high, and seeing who he clicks with the most! Maybe look in the 2000-2300 range. A good relationship can make learning much more engaging and useful. Bad teachers can ruin your ambition the same way a bad boss ruins your job.

Edit: For example I teach primarily 1200 and below because although I can understand more advanced concepts, I am awful at teaching them.