I'm not a
Cecil fan, but I love
Cecilia. It was my number one name last year (got booted out by
Fiona this year.)
Cecilia is classy, elegant, and vintage. I greatly prefer
Cecilia to
Cecelia- it looks more "correct" to me. Funny, but I used to think the opposite. As far as
Helena and
Cecilia go, I'm not too fond of them as sisters because they're too similar for me (both three syllables and both end in the same sound.) But I like them individually.