I dislike
Alexa. I work with kids and I see it all the time, and variants of it (In my student teaching class I had both an
Alexa and an
Alexia, and right now I have an
Alexandra, which is also my cousin's name, and there's an
Alexa in another class.) Also, I'm just not a fan of
Alex- names for girls in the first place.
Alistair I like. It's stuffy but I find that kind of adorable. I like the
Alistair spelling the best, but I also like
Alasdair because the idea of Dair/Dare as a nickname is appealing to me.
So I bet you can guess I'd say keep
Alistair, drop
Alexa.