Boy or girls name to go with Zack?

[Zacksmummy]

I'm due in early March and I don't know whether it's a boy or a girl. I'm hoping for a girl this time but still can't settle on a girls name and really struggling to find a boys name. I don't want something really common or anything very long as we have a long surname. Also don't want anything beginning with A, H or Z so that we don't get mail mixed up in the future!
So far in no particular order I have;-

Girl - Lucy, Gemma, Saskia or Lauren. (Today I'm liking Saskia as it sounds unusual but not way out)

Boy - Dan, Leo but struggling to find something I love as have lots of friends/family that have used up short names like Ben, Joe, Sam, Max, Mat so they are all out

Any comments or suggestions? Then just have to persuade husband as he has no patience for name books so just wants a shortlist presented to him!!

I like Xanthe for a girl
and
I can't think for a boy
(sorry!)

Zack and Jacob?

Zack and Sophia?

Lucy, Saskia are great, also like Leona

Boys names how about Jake, Marcus, Luca, Joel, Ethan, Nathan.

Thanks so far some interesting ones - hadn't thought of Sophia or Leona but like them too. Also was thinking about "Marcus" over the last few days too. I would love Lucy as a name but my husbands brother has just run off with a woman called Lucy so although hubby questions how long the relationship will last I'm not sure I now feel comfortable calling the baby "Lucy" if it does turn out to be a girl! Should I be selfish and stick with because we had already picked that name or should we be sensitive to sister-in-law and children and not give them a constant reminder?! They don't know the other womans name yet but it will come out soon enough I'm sure!