The more standard
Rachel spelling always looks like it's missing something to me.
Rachael takes care of that (and it helps that my dad's middle name is
Michael). But you seem to like
Rachel better, so we'll run with this spelling.
Rachel needs something far gentler as a middle name:
Rachel AmberRachel AminaRachel AmiraRachel EileenRachel MaureenRachel MayRachel Pearl
Off the top of my head. :-)