Some years ago, I started a project, armies of late antiquity in 28mm, I built a Sassanid army, almost completed, a Goth army (almost completed too) and a Late Roman, Patrician and Belisarian/Justinian army... the latter is my favourite, but, sadly, nobody produces proper miniatures for Justinian armies.
Inspired by venerable Warhammer Historical books, full of nice pictures of Perry and Gripping beast miniatures I painted some samples for my upcoming Byzantines! I say upcoming because Aventine Miniatures and Footsore, have announced that range in the "near" future!
Until that moment, I have painted some units for my Late Romans that can be used for those Eastern Romans.
First, a test model for a unit of Belisarius' personal Bucellarii, as seen in one Kevin Dallimore's book, published by Foundry, with some pics of Foundry's Late Romans converted into Belisarian Byzantines... here you have my personal approach:
I also painted an "Army standard bearer"converting lightly a Foundry Cataphract, I just copied or try to emulate a photo of the book "Fall of the West" by Warhammer Ancient Armies: