When I daughter transferred from PEA to Milton, she didn't have to take the SSAT again. But that was because she took it the year before. You should ask, she did, and Milton waived it.
As for TOEFL, it all depends on your English skills. If it's not good, then you would benefit from the TOEFL. IELTS is fine too. But you should find out from individual schools what they want to see.
You need grades from last 3 years to send to the schools you are applying to.