Visit http://farmaco0066.unimaas.nl/jo_co/figurist.htm and contact the webmaster. If I remember well he did some research on names like Fazio/DeFazio/Fazzi and other simmilar surnames. His name is Gregorio and you can write him in English or Italian.
I, too, am researching this Surname. You may want to take a look at the FAZIO/DeFAZIO/DiFAZIO Surname research page that I have assembled. It includes email addresses of a number of individuals in the U.S., Italy, Brazil and Argentina that are researching families with this name.