I prefer Cairo but out of these id probably go with the spelling Kylo. Kailo is cute too like an addition to Kai, but it might accidentally be mispronounced as kilo?
My nephew spells his kylo
My nephew is Kylo
I would spell it Kylo.
love the name kylo!
Kylo is awesome yet i do read it as Kilo
Cute name but definitely too Star Wars