Complex sentence: Cusumano is the spelling used in western Sicily and "Cosimano" is found in eastern, with many other variants but, also conforming to a lot of known dialectal conventions of those parts of Sicily.
Split into simpler sentences: Cusumano is the spelling used in western Sicily and "Cosimano" is found in eastern Sicily. There are also many other variants that conform to a lot of known dialectal conventions of those parts of Sicily.