There is absolutely no evidence of an Aramaic original for any of the Gospels, so the safest interpretation is that Greek is the original language for all of them. They don't read like semitic translations, although many Jews were Hellenized by then and many were fluent in Greek and Latin, so it might still have been written by Jews.
The evolution of Christianity is by adding narratives to the septuagint Bible translations, not necessarily by creating translations of new Jewish narratives. The names, as they appear in Greek, are therefore the correct original names, and Jesus is Jesus (or most accurately Ye-sus). In Hebrew, Jesus is translated back from Greek as Ye-Shu, and this is the best redering of the name, since it is a Greek Jewish name, not a Jewish name translated to Greek.
There are those that try to marry biblical narratives to history, and deduce that the Jesus described in the Gospels must have been a Jewish fellow named Joshua. There is no textual evidence for this position, or historical evidence. The best hypothesis is that the stories of Jesus were written in Greek, as original narratives, loosely based on some vague Jewish sect traditions, but mostly based on merging Jewish and Greek traditions into a coherent whole.
The new testament contains as much Greek thinking as Jewish thinking, and it is a mistake to over-Jewify it. It is anti-Leviticus, it is against a literal law-reading of the Bible, and supports an internal spiritual tradition of eternal life, which is mirrored earlier in Plato's philosophy of eternal forms, and is Hellenistic. That some Jews were firmly in the Hellenistic tradition does not make the New Testament Jewish, although much of it is Pauline.
There is no historical reason to view the events depicted in the New Testament historically. Of the new testament figures, basically only Paul is a recognizable historical guy, and perhaps James the Just (who is mentioned by Josephus). Everything else is religious narrative, which is not reliable history, only (mostly) reliable spirituality.