I think
Keira &
Annika are lovely names for twin girls!
An since you're doing
Keira Anngelique why not pick a middlename that starts with K for
Annika? I like
Keira better than
Kyra.
Blade
LeAnder is really nice especailly because it has so much meaning attached to it!
I don't really like
Jacenty Ki but I really like
Shay for a boy.
Looks like you're on the right path, just a little more playing around with the names and you'll have the perfect combos! :)

Bunny,
Gigi,
Chloris,
Wilma,
Darleen,
Eartha "Any name is beautiful when it's given in love" -Me