13. Antonio Stacklund: Items to upgrade your weapon. Venom is dropped by garbage fleas, particularly the ones near the robots. Waste collectors drop Compression Chambers. 32-V Dockers (robot) drop power supplies & optical item for range meter. Fluid Samples & Fuel Chambers drop from robot types, but not sure which robot type.
The remaining items drop from mobs outside the landing area ... Roller rats drop their intestines ... obvious I know. Reet beaks drop from Reets ... they are to your right as you head out into the desert ... they are higher level than mobs in the landing. Leets drop the Leet spine ... they are to your left as you leave the landing ... they are even higher level, mostly level 12 - 15. Angry Minibulls drop the leather hide, bone plates, and large skulls ... and they live up to their name. Angry Minibulls are straight out from the Landing, watch out for the Roller Rat, Sand Worm & Minibull Dyna bosses. Have your mini-map open so you can skirt by some of the mobs on your way to your destination.
edit: Rocket Launcher quest for weapons composites ... my froob could not get this quest, there was no option in the conversation with Remi other than asking if he sold weapons.