Are you referring to the program where you go to Boot Camp after your junior year and AIT after your senior year? If so, I'd advise against it. Simply because this is the time to be a high-schooler and have fun over the summer. Also, I'm not sure how applying to the academy would work since you're in the Reserve, but still in high school. This is NOT FACT, but I'm sure it would complicate things. As for SLS, I'd say it would be hard to do both. You can be in the Army after high school and for the rest of your career if that's what's for you, but for now just be a teenager and focus on grades and everything you can do to make yourself the most competitive applicant that you can be.