Make sure to fill out your resist, you want 75% fire/cold/lightning resist. Chaos resist is good, but not mandatory to have 75%, I usually aim for 30-50%.
Do note you will most likely need 1 high attribute roll on your gear (either int or dex) to fill out your attribute requirements - or you sacrifice 2 passive points for
Proficiency
Bow: You want the highest DPS weapon you can afford with critical strike chance -
Obliterator Bow is the go to base because it has extremely high base damage, but any bow base works - Any elemental damage also works because we're using
Plaguefinger
Voltaxic Rift Is an okay starter bow if it's cheap, the downside is the bow has 0 base crit so it'll quickly get replace by a good rare crit bow.
Quiver: Want high crit/crit damage with high flat damage, other good stats are increased damage with bows, atk speed and +2 level to bow skills.
Rings: You just want high flat damage rings, just like with the bow, the element doesn't matter because of
Plaguefinger
Gloves:
Plaguefinger is by far the best in slot option, makes gearing extremely easy as it allows you to stack elemental damage on rings/bow/quiver and allows you to use strong unique jewels.
These gloves are very strong but not mandatory, you can play this build with pure phys on weapon/rings, it'll just be lower dps. If you don't have these gloves than the ele dmg on your gear does nothing.
Belt:
Headhunter is always the best in slot for mapping, but never needed. Just use a regular rare belt with str/resist/life if you can't afford HH
Amulet: The only mandatory stat here is 30 spirit. Besides that crit/+level to proj is always good for damage. Global defense/increased energy shield are good for defense.
Helmet: You want the highest energy shield helmet you can afford, this is very important for defense because you take
Subterfuge Mask
Body Armour:
Hyrri's Ire Is easily the best in slot but not required, if you can't afford it just buy the highest evasion body armour you can afford, preferable with deflection rating.
Boots: Just want high movement speed and either life or %ES/Evasion, preferable with deflect rating.
Jewels: Get one jewel with %mana on kill, this will make your mana feel extremely good for while mapping. For unique jewels,
Against the Darkness with any extra mod is fine (cold/fire/light/chaos)
Heart of the Well with 2 gain extra mods is also ideal.
For regular rare jewels, you just want crit/crit dmg/magnitude of poison
4 Mod Rare Radius jewels are also extremely strong but will be expensive
Anoint:
For damage:
Lasting Trauma is what I recommend.
For defense:
Patient Barrier Decent option for more ES
Cheap option:
Serrated Edges