The easiest way would bew to purchase in your wife's sole name, if they were to come out of your wife's funds that would guarantee any future claims form third parties (i.e. your daughters).

However, according to §46 of Law 218/1995, the general law is that the inheritance law is that of the deceased's nationality. Therefore the problem is how you would go about it in the UK.
Italy could have jurisdiction (applying the deceased's national law) if the deceased was an Italian citizen or resident there at the time of death, or if there is a question regarding property in Italy.

As already said, to assure your wife proprietorial rights over the property under Italian law, the best way would be to purchase the property in her sole name with a contract in which she declares that the property is only hers and it is not to be considered as being joint property, and in which you also intervene accepting that it is to be considered solely hers.

To guarantee yourself, you could keep for yourself 1/2 of the "usufrutto" or use of the property, therefore though your wife wuold have propertorial rights, you would have beneficial rights over the property until sale of the property or death.



While I don't know the details of property law in Italy, the safest way to assure that your wife has sole claim on the house is to buy it in her name only, using funds that already belong to her.