I prefer Naomi but yes, there is the pronunciation thing. I know three, who all pronounce their name "nay-OH-mee", but who frequently get "NIGH-oh-mee" or "NAY-uh-mee", which can be a bit annoying.
Lucy is a nice enough name but a bit vanilla IMO; however, you shouldn't ever have any problems with the pronunciation of it so if you think that would bother you, I'd choose Lucy.