The LMC catalog has great diagrams that show all of the front end components, but it's pretty simple as to what wears out in our trucks: EVERYTHING !
That's right. I'm not being a smart a$$, but basically every component is a high wear item in the front end. They wear out faster when there's a lift kit installed, the T-bars have been cranked up pretty high or wide tires and wheels with too much positive offset have been used.
The basic check list is: idler arm, idler arm bracket, inner and out tie rod ends, pitman arm (on the steering box),upper and lower ball joints, upper and lower control arm bushings and the end links for the sway bar.
The best quality parts to use for a rebuild are Genuine MOOG parts. Expect to pay around $700 for all of these parts, plus installation labor if a shop is goin to install them.