Freeman: Guerrilla Warfare – Which Bandits Drop What

Just a quick access on what to farm to get a certain item to equip your units with in decent quantities.

Optimal Farm

Money: Cossack Rebels; since their kevlar can be sold or 9k each and they usually have lots of prisoners thanks to their strength. Terrorists are better for profit if you find any but they feel less common.

Kevlar: Cossack Rebels [55 armour; jungle camo] or Terrorists [60 armour; night camo]
Helmets: Cossack Rebels [30 armour]

Assault Rifles: M416 from Terrorists
SMGs: Vectors from Armed Convoy Guards
Shotguns: Delete yourself; otherwise Armed Convoy Guards for half-decent ones.

Loot

Desert Marauders
Police Vest Camo [42 armour |12 Jungle camo]
AKM
AKS76
Miniscule amounts of various camo clothing

Cossack Rebels
Heavy Kevlar Vest [55 armour | 13 Jungle camo]
Old Helmet [30 armour]
AK12
AKM
Camo Masks
Miniscule amounts of other various camo clothing

Terrorists
Heavy Tactical Vest [60 armour | 13 Night camo]
M416
AK12
AKM74
TT56
Black Shemagh
Miniscule amounts of forest camo clothing

Armoured Marauders
Police Vest [42 armour | 15 Night camo]
AKM74
Gas Mask [5 armour] 
Black clothing

Pirates
Police Vest [42 armour | 15 Night camo]
PDR