Ciao J-froms!
From what I've heard, UCLA has a very strong Italian program. I met someone at a conference a few years ago doing his Ph.D. there who was very happy with the program (and now, post-graduating, has a great professorship back east!). I know there is an Italian consortium (CICIS) of all the UC schools; they have conferences at least annually. I'm not sure about the dialectology/sociolinguistics aspect you are interested in, but if you'd like, private message me and I can give you the email of the guy I met at the conference, who might be able to better answer your question!
Forza ragazzi!!