The examples on Google with ni-gamma were:
http://www.lgpn.ox.ac.uk/publications/vol3b/vol3b_names/v3bme_u.htmlSince this link is from the Lexicon of Greek Personal Names, by Oxford, the 5 occurrences of Evangelos are correct.
http://www.greece.org/hec/hecbylaw_gr.htmlIn this website, the form appears as name of a person from Greek descent. But since he is from the USA, it is probable that his name is
Evangelos and
Ευάνγελος is just a transliteration to Greek (more or less like some Irish names Anglicized and later reIrishized having the English form as base).
http://www.parrocchiasantavaleria.it/lettori/incontri/Lettori01.pdfAn Italian webpage about the Bible and the Gospels. But since the word is even spelled
ευανγέλοσ, with σ instead of ς, the realiability of the source is very doubtful.
http://es.wikipedia.org/wiki/Evangelizaci%C3%B3nThe Spanish Wikipedia, mirrored in some other websites. (The English version have the spelling with gamma-gamma, even it says "transliterated" when it obviously is not a transliteration but a transcription.)
Lumia
http://onomastica.mailcatala.com