I'd pronounce Kailey as Kylie because of the 'ai' (hence i spell Haley not Hailey -same reason)

I also went to school with a Kayleigh.

I like Kayley out of those options.
For me the L after tha AI changes the sound of the vowel. Like in hail. If I saw Kai as a name I'd pronounce it Kye but if I saw Kail, I'd pronounce it like you do hail.