Crossbow most important item: BIG phys dmg + flat lightning. For the suffixes get 6 mods and use Perfect essence of Battle and Perfect essence of haste to get both essence mods.
Gloves: HIgh flat damage + resist + evasion/es/recharge.
Boots: As high movement speed as possible, can look to make essence mod boots if rich. ES/Life/evasion + resists and dex or int.
Jewelry: HIgh flat damage + Resists + dex/int.
Amulet: +3 Proj and spirit are best so you can run a Cannibalism II. Other stats are resists + %ES
Body armour: High EV/ES + resists and attribute on a falconers for movement speed.
Helmet: HIGH Energy shield to make use of
Subterfuge Mask and resist/attribute.
Belt:
Headhunter eventually but until then just life + Resists and attribute, early survivability can be
Shavronne's Satchel.
Attributes are insanely annoying to get on this build so you do need several suffixes with int/str/dex so you can get enough for both the offhand weapon/ES gear and gems.
**NEED OFFHAND BIG PHYS BOW/QUIVER FOR
Stormcaller Arrow SHOCKS**