I like
Lorelei personally, it sounds softer and more youthful. Plus, I like the the mythological connotations. There’s a poem by
Heinrich Hein about the
Lorelei (can’t remember how the name is spelled in the poem, it might have been
Lorelai) that I always liked, so I tend to think of that.
Helena is alright. It makes me think of
Helena Bonham
Carter mostly, which is kind of cool, but I don’t really have any other associations for the name so it is kind of neutral to me.