Syracuse would NEVER agree to play us at CA, and at MSG they get a bigger crowd, so not them unless it is a neutral site.
Duke is up there for me, because of some of those times when we really stepped it up, even in that Ronnie-led team that lost in OT (what a game)!
Davidson is a nice team to play and with McKillop always well-coached, and can be formidable, same for Huggins and the Mountaineers.
Gonzaga being a smallish Catholic school (new BE similarities) makes a certain amount of sense, except for their distance and them having no NYC connections to speak of.
How about schools like Georgia Tech, etc., places that have beaten out SJU for the NYC talent over the years.
Last, I wouldn't mind ND, it is very enjoyable when a real "blue collar" school like St. John's goes up against the smarmy, entitled, Catholic "Ivy"! I can hear the ND fans at the Garden now, "YOUR FATHERS WORKS FOR OUR FATHERS" (tongue planted somewhat in cheek). Anecdotally, I heard that the Duke student section used to chant that to certain of their rival schools.
(And actually any kid from the NYC area who can get into ND should go there, the connections they can make there are invaluable).