This is just my thought; I'd use at least 2 pieces heavy (chest and legs) for some extra mitigation. To make up for the lack of 2 light pieces I'd probably run Kagrenac's instead of Julianos.
Valykn used to be great, but I've heard a lot of complaints since the DoTs were nerfed that it doesn't perform as well, so I'd most likely use Bloodspawn. As a DK you want as much ultimate as possible, and Bloodspawn can help there. A little bit more stam regen doesn't hurt on magicka classes any way.
Willpower jewellery is always good