We had Magna Cum Laude and Summa Cum Laude. Magna Cum Laude was for 4.00-4.25 GPA, and Summa was for 4.251-5.0. We probably had about 10% of our class of 300 end up Summa cum Laude.

But we also had, like, "Graduating with Distinction" or something like that that seems a bit more like your deal. Certain requirements about the amount of English classes taken, 4 years of math, 3 years of science, 3 years of a foreign language, but I think we had an option of either taking 4 AP classes scoring at least a 4, OR a senior project. Nobody did the senior project, and I'd say 15-20 of us ended up graduating with it.