PEA admissions are totally “need-blind” like Andover? Please, tell me more about it. 
Thank you!
PEA is not need-blind.
As I hinted at on your recent PA thread, the forum rewards people who do their “homework” (search and read the many existing threads on pretty much every topic you can imagine) vs. just posting random broad questions.
Many waves of applicants have applied to the schools you have expressed interest in…and chance are many of them have had similar questions. And many have been asked — and answered here on CC. So take the time to search, find, and read them. Another suggestion is to write PMs directly to people seem to be knowledgeable and relatively current contributors to the threads you have found.
PEA is not need blind for internationals (see their admissions info), but total financial aid is generous and over half of students receive aid, with the average award being large (also on their admissions website). The total amount of financial aid given is pretty comparable between the two schools you mention, with a few wrinkles to make it hard to compare directly (Exeter does not count tuition for children of faculty as aid, others do).