I would definitely choose
Lydia before
Leah and
Julia, just b/c
Lydia is more uncommon.
Lydia Bennett is not the only literary character. I liked Lyddie by
Katherine Paterson.
1)
Lydia2)
Leah3)
Julia
But all three are beautiful names.
Lidia is a Slavic spelling, I would only use this if I had roots from Russia etc.