Well, the Web is back with at least a few searchable, complete texts of at least some of the Greek Fathers. Check out Thesaurus Linguae Graecae. It’s a research center at the University of California, Irvine, and it’s been working since 1972 to collect and digitize literary texts written in Greek from Homer to the fall of Byzantium in AD 1453. “Its goal is to create a comprehensive digital library of Greek literature from antiquity to the present era.” TLG has posted quite a few sample texts, most of them classical, but not a few patristic. On a quick scan, I found Clement of Alexandria, Basil the Great, Gregory Nazianzen, Gregory of Nyssa, Origen, Maximus Confessor, Romanus the Melodist, John of Damascus, Cyril of Alexandria, and Ephrem of Syria. Happy browsing!
Hat tip: David Scott