I went with Voyage Jules Verne and prebooked two trips with them. The Amalfi drive, returning by boat and Pompeii/Herculaneum. Both a must for this area and not to be missed.
Interestingly, they also did a trip to Capri, but were not recomending it due to a variety of factors! They suggested for Capri DIY and get the ferry from Sorrento to the Island. Once there, do your own thing away from the very comercialised tourist traps. A beautiful place I gather. I believe Ischia is just as good but less commercialised.
I did a DIY to Naples by ferry instead, after doing Pompeii. This was a great day out. Only the Neapolitans could make driving into an art form. Red light ! What red light!!! Pavement! What pavement!!! Great place, but do be very careful from a security point of view. Be sensible and you will be ok. Leave expensive jewlery etc back at base. Its no worse than any major city these days. Especially see the Archeological Museum, all the original artefacts from Pompeii are here and they are a wonder to behold, amazing. Great shops here too.
Sorrento is wonderful and I would certainly do it again.
Where are you staying?
Hope this helps.
Peter