My favorite spelling is
Kaitlin. I just like the -lin ending far better. Would you ever consider using
Carol? I feel like
Carol has a very reto-cool, 40's, 50's, 60's vibe to it.
Kaitlin Alexandra Carol is fine, it might be a bit clunky...
My favorite of your combos are:
Kaitlin Alexandra Juliet, it has a sweet, elegance to it that I like.
Kaitlin Alexandra Pearl, has that nice retro-cool vibe that I mentioned earlier
Kaitlin Alexandra Claire is a nice classic pairing.