Not sure about pronounciation or meaning, but if Italian names are anything to go by, an English equivelant would begin with a 'J' like
Giovanni=
John,
Giustino=
Justin and Guiseppe=
Joseph. By the looks of it it's probably a combanation name like the Italian
Giampaolo is a mixture of
Gianni and
Paolo=
John Paul. Sorry, I'm not much help on Italian names:(