I have a daughter in eighth grade and we have some experience with the programs that were mentioned in previous comments.
We are currently waiting for M10 decisions and hoping for the best! 
- I support the postings about Davidson Young Scholars Program. It is a great program where you are connected to parents who are or have already gone through similar situations. It also has an annual summit where we get to meet other young scholars and their parents. The summit offers hands on classes for kids and lectures for the parents. We also toured the academy a couple of times. Yet, my daughter didn't wanted to apply for its academy for some personal reasons.
- Early college : She was accepted to an early college program when she was in 5th grade. We talked about it extensively but ultimately, she did not want to go because she wanted to be with her friends. So it was her young age that dissuaded us from accepting.
- Caroline D. Bradley scholarship: Since your child is in 7th grade, give it a try. I believe it would cover tuition for early college as well. Contact them for more info. I believe that it is a wonderful program.
- Local 2 year colleges: I agree that they are beneficial. The classes provide great opportunities. My child received a scholarship from one college's math department in return for her participating as part of their team in a national 2 year college math competition in which she did quite well on.
I believe taking SAT early was somewhat helpful see where my child’s academics were compared to others. In seventh grade, she scored a bit below 2300 on the SAT and was able to ace the SSAT and ISEE this year without much preparation (only 1 wrong on each test).
My child prefers to be with her age group. So I guess the early college option is not for my child. But everybody is different and it might be a good option for your child. My child and I believe that boarding school would be the best option for her.
Good luck! I’m sure that whatever path you guys agree on will be the best one for your child.