I'm a really huge fan of Cai/Kai as a full name or nickname for either gender. So I'd support just about any way to get there. :) Caia sounds really pretty. I'm kinda tempted to make it
Kaia, but Caia does feel less trendy, what with Ks being so big right now.
Hold it, I just looked at the pronunciation you wrote. Did you mean to put the accent on the second syllable? I'd pronounce it KYE-ah.