I would expand your set of schools. Also, the schools to which you are applying will understand your 1-10 grading system. If you are lucky, they may even have had other students from your school in previous years. Your EC’s seems excellent and well varied. Your SSAT scores are very low for those schools. The English portion is understandable given you are not a native speaker but the math portion should be even more solid. Remember they want to ensure that you excel. Do you have someone at your current school who knows about US boarding schools? If not, I’d work on getting your scores up and writing good essays.