I love this whole family of names.
Fiorenzo reminds me of
Fiorenzo LaGuardia, an ex-mayor of New
York.
Fiorenza is such a fun, frilly name...wish I saw it half as often as we see
Isabella,
Evangeline,
Anastasia, etc. I think they're both a little tricky/unfamiliar to Americans who aren't Italian or from New
York.
Also love
Fiore, but that would probably be butchered even worse in English, and almost certainly wouldn't be taken for a girl's name at first sight.