If you want heavy infantry in a medieval setting there is no better way to go than full plate. It also comes in size horse.
[hider=horse armor][img]http://upload.wikimedia.org/wikipedia/commons/4/48/Dresden-Zwinger-Armoury-Armor.02.JPG[/img][/hider]
It would suit the Balenian culture pretty well since you've described them as strongly aristocratic. Each armor has to be tailored to the individual user, this would mean that every nobleman's armor would be unique and can therefore be "pimped" to suit the wearers house or style.