Things absolutely needed for the swap are
-M5R2 Trans
-SC flywheel
-SC clutch
-SC slave cylinder
-Pilot bearing
-Clutch hydraulic line
-Clutch slave cylinder
-Clutch master cylinder and reservoir
-Clutch Pedal
-Driveshaft
-Shifter
-5-speed console top
Other things that it would be nice to have are
-Engine separator plate. The auto one will work, but won't cover the whole area where the flywheel is.
-5-speed shifter plate (bolts to the floor where the shifter comes through to seal it up
-B&M Ripper shifter (makes a huge difference in the way the trans shifts)
-New slave cylinder (don't want it to go bad and have to drop the trans out to replace it
-Trans crossmember (one from an auto can be made to work, but if you can get the manual one, it will be one less thing to do_
-Aluminum driveshaft (stock 2-piece is no good for high performance, so it is a good idea to upgrade)
-Clutch interlock wiring, if you want to wire it into your starter or cruise control. Personally, I just leave that out.
-Brake pedal from a 5-speed car. The alternative is just to cut down the pedal portion of your stock pedal and install a new pad.
-Gears. M5R2s work better with shallower gears in the rear. If you have the stock 3.27s, that might be OK, or you might want to swap to 3.08s or 2.73s. If you have changed to 3.55s or higher with your auto, you will definitely want to get something closer to the stock ratio in there.
The ECU is not needed for a swap in an 89-93 car, since that trans isn't controlled by the computer. There will be some calibration differences, but that could all be changed in a tune if you want, so there isn't any particular need for the manual trans ECU. The car will run and drive just fine with the auto ECU without a tune or anything. If swapping into a 94/95, you will need either a tune or the manual trans ECU.
The clutch line can be hard to find in good condition. It is possible to make a new one using adapter fittings and AN lines, but that would put the trans side connection inside the bell housings, so if you need to drop the trans, you will need to disconnect it from the master cylinder, and then re-bleed the system, as opposed to the quick disconnect factory fitting, which prevents air from getting in when it is disconnected.
One other comment on this swap; pull the dashboard out of the car to do it. There are many write-ups that say to cheat and use a right-angle drill to drill the holes, and then cut a tab off the pedal to bolt it in. Pulling the dash isn't that hard, should take maybe 2 hours tops to get it out of the way, and another 2 going back in, and that is if you have never done it before. Modifying the pedal to not have that tab that bolts to the cowl panel is just asking for a cracked firewall, and by the time you mess around with leaning under there trying to get enough room to drill the holes, you'll probably only save about a half-hour of time, so don't even waste any time trying to figure out a way to not pull the dash. Just pull it out, drill your holes, and mount your pedal. It may take slightly longer, but you will be able to see what you are doing and where you are drilling, and you won't be laying on your back getting metal shavings in your face the whole time.