That is quite "Black"quese
Without a doubt i would go for the Italian player.
You can say that according to the origin of the Club Internazionale,it welcomes any players regardless of nationality but those circumstances were very different. I don't want to act pedantic and know it all about the Club and its history but during those times, Bilan didn't welcome International Players and thats why the need for welcoming international players arose but now times have changed and no Club, Bilan included, has a restriction on the foreign players, apart from the regulation imposed by EU, so the initial reason doesn't hold as strong as it was.
Also, bringing local based players would have a special meaning for the supporters. They might continue supporting regardless but having a local player /Italian Player certainly creates a special bond amongst the supporters. Also giving the example of few local/Italian origin players who had chosen other clubs over us doesn't help because if you take an average of the players and their affinity towards the Club the local players would have that extra reason to stay at the Club.
Also lastly, people who come down to the stadium week in week out definitely deserve more recognition than people who are supporting them from outside. I am not saying that people who are supporting from the Net/TV are less genuine than the ones who are in the stadium week in week out. its a highly contentious debate and i have my own personal opinion about it. But definitely the ones in the stadium would have to applauded to be there. And cultivating/buying Local/Italian players should be a priority as a tribute to the local supporters as well.