I don't think the true origins of hoplites are known except they seem to coincide with the rise of the polis, Greek city-states, and declined during the Peloponnesian War.
There are currently three different sets of theories on the development of the Hoplite, but basically the pictorial evidence from painted pottery, sculpture, etc. points to a transition between 750 and 560 BCE possibly with a period in there where they were fighting with both the heavy thrusting spear and throwing javelins first (javelins apparently being the weapons of choice during the Greek 'Dark Ages' before 750 BCE). Hoplites, except in Sparta and a few 'elite' organizations like Thebe's Sacred Band were always Upper Middle Class Militia, providing their own weapons and armor. Since the Peloponnesian War lasted almost 30 years, the Hoplites couldn't afford to spend all that time away from their farms, so paid mercenaries began to take their place, and the mercenaries started fighting in looser formations with lighter 'sets' of arms and armor - enter the Peltast, which increasingly replaced the Hoplite in the 4th century BCE (Iphicrates of Athens is credited with starting to use Peltasts as his primary infantry force around 390 BCE) but some smaller city states kept a Hoplite Phalanx until almost the end of the Hellenistic period.
Greek Science was derivative, but Greek Engineering and Applied Science was surprisingly unique:
Lime Mortars (primitive concrete) was being used in Greece, Crete and Cyprus around 800 BCE - end of the Greek 'Dark Ages'
Grooves were being cut into large masonry parts to guide them into place by 665 BCE - an architectural technique not, as far as we know, derived from the Middle east or Egypt.
The earliest firm evidence for the Trireme, the 3-banked galley, is from Greece in 542 BCE, despite claims that it was invented by the Phoenicians.
First evidence for cranes and other mechanical-advantage hoisting machinery used in masonry construction is from Greece (Corinth, to be exact) in 515 BCE.
The first evidence of iron bars used to reinforce a stone structure is in the
Propylaea on the Acropolis, built 440 - 430 BCE.
Sticking to Classical Greece, then, we could legitimately have a Greek Unique bonus to constructing monumental structures - like Wonders.
Unique Building: the
Agora, the "market place" and also political forum, voting arena and center of every Greek polis. It has the advantage of potentially showcasing both the City State Politics and the individualistic Culture of the Greek city states.
Another Unique Building: The
Akademe (Academy) or
Lykeion (Lyceum) - Schools for Philosophers both of them, their in-game Unique ability could be to attract Great People at a faster rate, which neatly shows off the popular view of Classical Greece as a home for Great Individuals.
Unique Unit - stepping away from the Hoplite for a moment:
Trireme
Peltast
But even better would be to make a Unique out of the City State differences among the Greek polis: I like the idea of changing your Capital at some semi-random point to reflect the fact that no one city state dominated Greece for long.
Let's take it a step further, and when you change city-state Capitals, you also have the option of changing one of your Uniques: UU, UB, UA. That way the Greek Civ could potentially cram in all the variations.