What parts are needed for 4 speed conversion?

Search the Manual Transmission & Clutch Discussions section, all of your answers are in there.

"How hard can it be???? You running a slant or v8? Slant don't need much. Trans. Bell housing. Pedals. Linkage. Fork. Zbar unless you go hydraulic, driveshaft flywheel and those bolts, clutch and fork. Shifter. Boom. Done"

Not quite my friend. A lot more involved that you think. Ask me how I know?
Plan to shell out around $2k + for parts, that's if you will do all of the work.