Return of Reckoning

I'm currently levelling a KOTBS, around level 20, and I am strongly disliking the appearance of my current armour (just a breastplate). Does anyone know where I can get hold of something with a significant amount more coverage? My IB and Chosen of approx the same level are just walking balls of ...

What are the most commonly used classes per role and faction for keep defences, and why are these so favoured?