That sounds like a great plan, you are already ahead of most of your peers for thinking ahead like this. I was in your shoes at the same age and got my PPL when I was 17 before my senior year. Just dont do what I did and get in trouble for skipping school to fly. I got more detentions my senior year than I can count for doing long cross countries on school days. Luckily the principal cut me some slack and never suspended me like he would have others because he knew the flying was working toward my career. The people in the office thought it was hilarious though that I was cutting school for something so productive....lol