Call the schools your family is interested in, and ask them which they prefer. If they won't say, ask them which the kids who 'usually' apply 'usually' take. You want to make it as easy as possible for the school to get to know your child, so make an effort to speak their language.
My son's boarding school was sort of a last minute thing, and they were fine with his previous SATs. Good for you for not going about it in a big rush!
Thanks for de-lurking, and I hope that this is helpful.
1) What schools are you looking at?
2) Are you hiring a consultant to help figure out which schools you might want to look at?
Smiles,
Grinity