We used a private company called Sorrentotopcar, which has vans for 6 or 8 passengers. We were on a cruise that had a port day in Naples.The will take you to Pompeii, and the Amalfi coast, but they are flexible and can arrange the day as you want. These are driver/guides.
You can contact him at
www.sorrentotopcar.com He can help you for any problem in Italy
