OP - your baby, your choice. And we don't all share the same taste in names, which is a very good thing, otherwise the world would be a much duller place. So these are just my thoughts - absolutely no offence intended:
Luna = the Moon. Pretty sound, quite popular; are you happy with the meaning?
Lux = to me, means soap flakes. As you know, the word Lux was Latin for 'light'; Lucy or Lucia share the same origins but are not brand names. And, to me, sound much less ugly, and don't rhyme with the f-word...
Alaska = makes me think of that right-wing US female politician, and of snow and huskies and oil exploration. Sorry, am not a fan of place names as personal names.
Jackson - am not a fan of surnames as first names, either, unless they commemorate a family member. But I think I'm in a minority!
Austin - a good name. I rather prefer the longer versions Augustin or Augustine, but that's just personal taste.
Sonny - fine, but always seems like a nickname rather than a 'real' name.