If you like SAS, check out Dublin School. Much smaller and in rural NH, but the head of school is outstanding, a la Tad Roach.
If you like Groton, check out Thacher. Thacher was once known as the Groton’s Western counterpart.
If you like Thacher, check out SAS. Similar vibe, value orientation and size.
If you like SAS, check out Cate. Cate is sometimes called the small, closed-knit New England-ish BS located in the West Coast.
If you like Cate, check out Thacher.
I agree @patronyork - Cate, Thacher, SAS and Groton have a lot in common and a lot to offer. I would also say that if you like Choate, check out NMH and Loomis too.