On my stamDK I use wings for the reflect, fossilize, molten armaments for the heavy atm boost. Oh and the shield that gives major mending to buff vigor
@oneshot_onekill
As for your second question I missed it. Well skills that cost magicka normally scale off magicka. As for self-buffs like the DK's volatile armour, there are more than 1 components involved. Your max stam/mag or weapon/spell power do not affect the buff portion of the buffs Ie; the major ward for example will always grant that 5180 (cant recall exact number) increase to physical resist. However the other component of damage/shield scales of magicka/health.