During my career of wedding planning many brides and grooms had Italian heritage especially from Brazil and USA.
Many of them were coming from South Italy but for example Brazilian were coming from north, especially the veneto region.
How wonderful could be getting married in the homeland of your grandfather or great grand father? Veneto region have masterpieces of villas and palaces were you can get married, just let me know the village and I will let you there with an unforgettable wedding day. Another popular spot could be Matera and Basilicata, little stone jewels spread in this tiny Southern region just beside the most popular and expensive Apulia.
Recently I was asked also for Marche, very similar to Tuscany but definitely less expensive but still with outstanding countryside between the land and the sea.