If you go with the high school curriculum, I would talk to the high school about whether they would recognize classes taken in middle school. High schools in our area often won't honor classes taken in middle school. So, if the high school requires Intro Physical Sciences as a prereq for taking Chemistry, they have made kids take IPS again once they get to high school to meet that requirement. Talk about a demoralizing year of boredom for gifted kids. . .