Elena doesn't happen where I live. I'd pronounce it eLAYna. I love
Eleanor and
Elinor, which to me sound the same; but I greatly dislike
Ellen, and associate it with
Elena.
Helena has too many pronunciations jostling for position. I say HELena, but most people here would guess heLEEana, which is pretty much the Afrikaans pronunciation, and which I don't enjoy. I love
Helen for its mythical resonance and its clean lines, and would happily use it. In a straight fight between
Elinor and
Helen, I'd go for
Helen.