Ok man i did a manual conversion on a s13 180sx and this is what was needed:
Gearbox, ensuring it comes with clutch fork
Tailshaft,
clutch pedalbox, master cylinder and slave cylinder and the hydraulic hose to join the two up,
clutch kit with new release bearing and spigot bush/bearing
machined flywheel
flywheel bolts
ensure you have the correct amount of bell housing bolts
gearbox oil
gearknob and trim for gearstick
A brake pedalbox should also be a preffered inclusion as the you have correct pedal setup but we did just cut the auto one down as a cheaper option
I would prefer the manual diff as the ratios are shorter and make it drive the way it should from factory as in the 180 the auto diff is two high geared and creates problems with lag and general driveability
The auto computer can be used but if so the inhibitor/selector switch must be taken off the auto and placed somewhere, preferably in the engine bay and switched into the position of park or neutral so the engine will start, can be used as a handy immobiliser haha.. the dash light may come on for the auto or the power switch may flash with the auto ecu as it will register diagnostic codes
The reverse lights have to be wired into the reverse swith on the gearbox instead of the inhibitor/selector switch
When you first drive the car the gearbox will most likely be noisy as they sit around for a long time without oil in them but does go quiet after some driving, reccomend changing the oil in gbox after about 1000km to get rid of any shit from the gearbox
you will need drill bits and preferably a metal holesaw to cut firewall for clutch master cylinder to fit through
thats about all i can think of man just a guide hope it is of some use to you, have fun!