YOU SAY: From the top down, Georgios Zizos.. It is spelled that way only because we are assuming his name was George and I tried to spell it like it sounds in Greek. Sounds like "Yorgo".
The Greek name is Georgios (Γεωργιος). "Yorgo" is Greek-Russian-Venetian Dialect (Giorgio (Venetian), Yuri (Russian, Georgio (Greek), Yurgen (German).
Panagiotis has nothing to do with Peter. Peter was one of Jesus followers, Panagia=Pan-Holy=Madona was his mother. Two completely different names. Stick to the real name which is Panagiotis.
In USA they call Konstantinos "GUS" and Gus is a Danish name short for Gustav. Stephanos, Stavors, Isidoros are all called "Steve".
If you wish to find your relatives in Greece and information about your family's History you must use the real GREEK names.
So, George Peter Zizos is not correct because as you know his fathers name is Panagiotis.
On the top of your family tree, you have Panagiotis = Helen Xenou.
Xenos, a Venetian family going back over 1000 years. (Also known as Zen, Zeno, etc) Renier Zeno was the Doge of Venice 1253-1268. Marco Zeno was Duke of Crete 1272. etc etc.
Sophia Zizos married unknown had two daughter MAMAKOU. Doesn't that ring a bell? Her husbands name was MAMAKOS. Mamakos also a Venetian name that exists in Crete. MAMUKOS is a similar name found in Chios and Italy.
Zizos is a very new variation of a name. ALL persons around the globe with the name ZIZOS not only related but VERY CLOSE related.