Before writing for their birth acts, it is best (due to Italian naming traditions) to have their parents names, which can be obtained by getting US documentation.
Once you have this information & their birth acts, the LDS Church (Mormons) have filmed the civil records (birth, marriage & death acts 1809-1900) for Gissi, Guardiagrele & Liscia.
If you need the film numbers and/or more information on these films or anything else, please let us know.
jcsm
Researching in San Vitaliano, Napoli, Italy & Armento, Potenza, Italy.