Antenati does not have Palermo. Bummer!
Familysearch dot org has a lot of Sicilia however it is all in Italian.
I am using the Atti di Morti, Atti di Matrimoni and the Atti di Nascita for Alia with good results. It is not digitally indexed, but you can find the handwritten indexes at the end of each year's book, or use the Indices Decennales.