The best reference for the setting is the Falcom Kiseki/Trails series which was used heavily for the general tech style inspiration - due to magitek in the form of Ether there is a basic, limited availability of things like computers (the Ether-net running on them) and mecha, a kind of magical industrial revolution with a lot of Steampunk-stylings if that makes sense. The Empire's tech capability closely resembles Erebonia in Trails (although a bit less in the way of cars and the like, still more steampunk in that respect) with the rebels having to work with whatever limited items they can find or fabricate.

Additional clarification for the Armors, they use Ether as a primary power source but tend to be fairly mechanical. The Guymelefs in Escaflowne (and this excellent sequence in the beginning) give a good idea of what the internals look like for Armor and how they move.