Medical insurance certificate/contract

Hello everyone, We have had such a frustrating time getting residency in our local comune in Sicily. It has been provisionaly granted pending the visit from the vigile, but we have been asked to provide a certificate of medical insurance. We are happy to do this and pay for a private contract to save all the hastle. Does anyone know of an economical way or company that can provide this for us in Italian and what we should expect to pay. regards David and Maria