Schools that focus on CS is more of a discussion for college, not for high school (BS or other). Better to search for a well-rounded school that is strong (or at least not weak) in science and math.
As for other schools, Google search for BSs in the geographic area you desire, or start with your favorite list/ranking of schools and gather as much data as you need/can about each. Sites like boardingschoolreview.com can give quick stats that can be helpful, including avg SSAT. You typically want to be above the avg for your matches and safties. The process is long and hard (but also exciting) and nobody’s opinion on this or any other forum about where you should apply should replace that process.
Speaking from experience, I’m sure geodiversity is helpful to your app, but do not consider it a hook by any means. Once the first 8 of 10 are eliminated and its down to you and a similarly matched candidate from NE, that’s when geodiversity will help.