I think
Caitlin would be best with something out of the ordinary--since the name itself is sort of the new
Jane, if you ask me. Made a bit plain by overuse.
Caitlin Lilias is my favourite of those you came up with.
Other ideas:
Caitlin TopazCaitlin IphigeniaCaitlin Reynada
Caitlin PerpetuaCaitlin IsadoraCaitlin ReginaCaitlin Orphea (or-FAY-ah)
Caitlin Justicia
Caitlin Seraphe
Caitlin FernCaitlin GeorgetteCaitlin UrsulaCaitlin EdwinaCaitlin VirginiaCaitlin PascaleCaitlin LucindaCaitlin Guinnevere
Caitlin VeronaCaitlin Parnassia
Caitlin Windaria
Caitlin OttilieCaitlin TryphenaCaitlin Esther
Array