I prefer Cato (same aa I'd pronounce Cateau, namely, kah-TO: like Château with a K)
It's the Dutch version of Cateau basically. I'd consider it for a girl as a let's say top 20 name. It was nr 48 on the Dutch chart last year, so people would assume Cato is a girl with the above pronunciation, not Cato as a male name which I'd pronounce the same but with the stress on the first syllable.
Cateau initially registers as a misspelling of Château (castle) to me and is too close to Cadeau (present, gift) for my liking.