The problem with 'Greek' armies is that they can cover a large time period and a massive expanse of territory. Generally we have the Mycenaean period (bronze age, time of Agamemnon and Achilles), then a dark age followed by the Classical period (time of hoplites, the Persian wars, Spartan, then Athenian, then Theban hegemony), then the Greeks are conquered by the Macedonians, Alexander spreads them to the edge of India and his Empire splits into Successor States on his death. There are a number of RTW mods that have researched the Sucessor State armies, so take a look at them for the 300 BCE-Roman period:
From the Extended Greek Mod.
From Europa Barbarorum:
Macedonia,
Seleukeia,
Bactria,
Epirus,
Greece,
Pontus, Ptolomaics.
I second Yang Liu's suggestion that you take a look at some of Johnny Shurnate's art. Some very useful stuff there. I have a feeling that a simple google images search may have been involved in both Yang Liu's and my seaches.
For the Alexandrian period you can do worse than getting some stills from the Oliver Stone movie. Whether you like the movie or not, he did try to get the equipment etc. right, and he had a number of good scholars working with him to make sure it was all authentic.
For the Classical period you've got most of the material you would need above. The main differences between the various city state's equipment would be in the helmets and shield designs. The Spartan ceremonial helms you have already done on your Spartan units, though in battle they would usually use the plain
Pilos Helm. The
Thracian Helm (used by Thracians and various mercenary units) I think you have used on your existing Thracian Mercenary Peltast unit. The
Corinthian helm was used through most of the Peloponese I believe. The Phrygian helm you have rightly used on your existing Macedonian units, and would also be used by many of the Ionian Greeks. The
Chalcidean helm was quite widely used even into the Roman period, and the
Attic helm was common in the Classical period (especially in Athens and the states of the Delian league). The shield designs I don't know a huge amount about, but some of the city states are covered in the various RTW mods, especially the Extended Greek Mod.
For the Mycenaean period make sure weapons are bronze rather than iron. Make sure there are no cavalry units - chariots are OK for this period, but not horse riding. Large greaves covering the legs up to the knees, a Bronze or leather cuirass covering the chest and an armoured skirt make up the armour. A javelin/spear/short sword and shield combo would make up the traditional arms. Apparently they practiced archery with short bows too. Shields were apparently like
the one that Virote used here.
EDIT - Just found some shield designs
here.