Here's a link that will help with Italian names and their English equivalents. Stephen equates to Stefano. The letter "J" does not exist in the Italian alphabet. In first names, it's Italian equivalent is the letter combination of "Gi". For example Giulia, Giovanni, Giuseppe, Giacomo.
I agree with Biff (having spent countless hours searching thru Latin Church records, which of course include the letter "J") With first names it is most commonly Gi, Giulia to Julia. Stefano is also correct, although Epifanio is often (but not as commonly) translated to Stephen in English.