You would need a tranny, clutch, flywheel, pedal assembly, equalizer assembly, bellhousing and fork, driveshaft and some type of shifter plus odds and ends for a 4 speed.
But I would suggest you find a 5speed out of a 86 - 93 V8 stang use a modified stock transmission crossmember and t-5 world class with bellhousing $800, yoke and clutch (no flywheel) from a wrecked fox body, and the rest all new components. Flywheel-$150, flywheel balancing-$50-100, shortened driveshaft-$50-100, clutch cable kit-$250, clutch pedal-$20-30, shifter-$50.
plus labor for both unless your changing it
But you could alway sell your car and just find a 4 speed car... hehe