Other pieces to look out for for your build are:
Pieces to break down in Kanai's Cube:
Dawn - Hand Crossbow. Will allow much better use of an essential skill for your build.
Cindercoat - Cloak. Cuts fire skill usage costs significantly. Your Multishot will be fire based.
Convention Of Elements - Ring. Cycles through the elements giving a boost to each. When it reaches fire, let fly continuously with Multishot.
Non Set Pieces:
A decent Helfire Amulet with passive that supports your build. Also make sure you have a slot in it for a legendary gem. Mine has Ballistics which is a requirement for the build, allowing me to also have Steady Aim.
Wraps Of Clarity - Beavers...actually Bracers. Will give a percentage bump to your Hatred Generators (Evasive Fire with the Focus Rune in Primary)
Dead Man's Legacy - Quiver. Great for Multishot.
Focus and Restraint - Rings. Get this set of rings and while playing, use Evasive Fire once every four seconds to give a constant 50% bump to all damage.
The Witching Hour - Belt. Just has really good roll potential for damage bumps for us.
Lgendary Gems (Get all to level 25)
Crits cause bleed and you get an attack speed bump for everyone bleeding.
Bain of the Stricken
Each attack against an enemy increases the damage it takes from you. With a 25% damage bump to bosses and Rift Guardians.
Bain of the Trapped
Increases damage to enemies under control effects. Applies slow to any enemies within 15 yards.
That's a lot to take in. Sorry.