Kizely (I'd pronounce this as Kye-zlee, hope I'm right!) is a gorgeously unique name, and I like the idea of wanting another unique K name to go with your LO.
Kahlyer I would pronounce as Kah-lee-er, so Collier makes sense. I personally don't care for this name in particular, but see nothing wrong with it as spelling is pretty straightforward and how it is said. I also really like the looks of this. Other options could be:
Kahlier, Slightly different Kallier (Kalli-err) sounds MUCH better IMO, and she could have nn Kallie. Kallie and Kizely sound really nice together.
Kuinlynn just doesn't work, if you as me. Quinlynn is one thing (still not a fan, honestly), but imagine her being nn Kuin. It looks very odd to me, and I absolutely LOVE "weird" spellings.
Other options:
Kenlynn (ken-lynn)
Kienna (key-enna)
Korhi (kor-ee)
Koralynn (Cora-lynn)
Kiora (key-or-uh)
Kenna (Ken-nuh)
Keelie (Keel-ee)
(I'm also from the USA)