Thanks! I figured it was more level-specific, with lower level characters being relegated to light and medium armor until they rank up a bit.

Heavy is pretty rare until the mid teens. My current is heavy armor and I was 9 or 10 when I got my first piece, by 15 I had all but boots. It wasn't until I got Ursine at 17 that I had full heavy. 

I'm aware of the Bear-School/Ursine armour set, but are there others? On my first playthrough I didn't run into very many pieces, and I went Cat-School. On this playthrough I want to go heavy but I'm almost level 10 and I haven't found any heavy pieces yet. 

Heavy Armour?