This is actually a re-post of a thread by Radioactive Ape, written in the context of a response to my Opelenean Nights thread.
The most appropriate style of plate for Opeleneans would be the Turkish "Krug", often worn over mail:
http://i4.photobucket.com/albums/y110/Nephtys/Medieval%20European%20Armo...
Similarly, for other armour, something like the Zihr (mail or reinforced mail armour) and Ciçak would get across the East-meets-West vibe:
http://en.wikipedia.org/wiki/File:Istanbul.Topkapi067.jpg
Weapon-wise, I'd replace the generic "scimitar" with the Yatağan and Kılıç:
http://upload.wikimedia.org/wikipedia/commons/thumb/f/f6/Imperial_Armour...
The plated mail was Zirah Baktar or Zirh Gomlek, and another appropriate helmet would be the Miğfer (pictured above with the mail).
Here's a Ciçak:
http://i4.photobucket.com/albums/y110/Nephtys/Oriental%20Warriors/acpi_h...
Also, do a Google Image Search for the "ak koyunlu helmet" for another style of Miğfer that would be appropriate.
ARMOUR
Opeleneans use the Kemeshi "Jawshan", a mail hauberk reinforced with metal plates (treat as lamellar). Over this they sometimes wear "Korazin" a light cuirass of metal plates, mainly circular, linked with mail.
Their typical shield is of leather- or fabric-covered wood or woven cord, often beautifully decorated, and is called a "Kalkan".
Their normal light helmet, based on the Kemeshi "Khula Khud", is the "Ciçak", and it features a tall, pointed dome, and is sometimes affixed with a peak, mail veil and aventail or cheekguards and nasal.
WEAPONS
They utilize a composite bow, called a "Tirkeş", and two different short-handled curved swords, the forward-curving "Yatağan" and the heavily-curved "Kiliç".
The Opelenean axe of choice is the single-bitted, highly-curved "Ay Balta" or "moon axe" a weapon often highly-decorated and engraved with a long steel shaft, found in battle axe and great axe varieties.
In terms of bludgeons, the "Topuz" is an Opelenean mace of all-steel construction with a rounded head, and is often engraved, inlaid, and otherwise embellished as it is a symbol of rank as much as a weapon.
Flails, "Döğen" are not uncommon, and most are normal wooden hafts with single chains and spiked iron balls.