In general, the prehistoric archaeology of southern Italy seems pretty obscure. I worked on the Intenet and through emails to a half dozen professors in Italy, England and the US before our trip to Puglia, and found no information useful to "tourists." Campania is so Roman, nobody seems worried about its prehistory.
It's a shame, too, because Italy has an incredible history spanning the paleolithic, neolithic and all the rest. But it's not set up for tourism or even the interested amateur. There are archaeo museums in Bari and other places in Puglia, but I never found any info on any in Campania. You have to be reading the professional literature, most of it in Italian, and even then I don't think the "sites" are much more than old, closed digs. Sorry I can't be of help. Wish I could do more.