Depends if free or for cheap. But free/cheap I would grab the
GP harnesses
Injector lines and injectors
IP
Air cleaner and snorkle
Fan, shrowd, radiator, overflow tank
Alternator and all the wiring to it and the regulator
Oil cooler
Starter
Low vacuum switch (Tuna can)
Any nick nacks you need in your cab that are missing or broken.
Clutch pedal
metal plate around stick shifter
ZF5 and related parts mentioned above
Tranny cross member