I think you have a decent chance at Lawrenceville, although you could use a few more extra-curriculars as well as your grades are a bit low for these schools. Your SSAT score is great! I’m in the process of applying myself too! (Although not to Lawrenceville)
Chance for chance? http://talk.collegeconfidential.com/what-my-chances/1860844-what-are-my-chances-of-getting-into-prep-boarding-schools-please-help.html#latest