I assume by the time you are reading this, you have already returned from your holidays.
In Sicily, I had the most pleasant experience shopping at Narcisse. In Napoli, while I couldn't visit the famous Alla Violetta, I sampled some of the more traditional creeds at Cilento, a house that specializes in leather goods and tailoring.
Eau d'Italie at the hotel Le Sirenuse in Positano, Carthusia in Capri (or in many other cities...I bought my Ligea at the Positano store). Carthusia is very affordable and I was pleasantly surprised by their fragrances.
Olfattorio in Rome was lovely. I didn't have time to go to the Campomarzio store but I'm sure it is wonderful and hope to visit next time.