I'm by no means an expert at this topic, but I saw it was going unanswered so I'll take a stab at it & perhaps someone will come along and criticize & help steer you to a viable option. With that said, one of our local club members put a non-dual-mass e30 m20 flywheel in his e36 m50 and it really opens it up & lets it rev freely. He was surprised at how much it improved the bottom end. I'm thinking about messing with this on my wife's e36.
He mentioned something about messing with the throw-out fork (different model?) and used a correction: e21 323 throw-out bearing (not e9 320). I would assume he also used the e30 disk & pressure plate. It was all nuts & bolts.
There are also numerous aftermarket light weight flywheels but I'm reluctant to going too light as it can cause driveability issues. It can suffer from annoying oscillations when taking off from a stop & actually lose a little top end.
As for the specifics for doing the job:
1. put all 4 corners up on jackstands
2. drop the exhaust
3. unbolt the front of the driveshaft & pivot it to the side & tie it out of the way
4. get a cheapie scissor transmission jack
5. support the trans & remove the crossmember
6. lower the trans slightly (make sure the fan clears the radiator, remove if necessary, make sure there's clearance for the head against the firewall
7. undo the clips on the shift lever link rod & remove
8. lower the trans enough to get room to reach the top bell housing bolts (see #6). With e32 & e34 m30's the engine will rest nicely on the swaybar. Use about 30"-36" of socket extensions & a mirror & flashlight to get to all of them. It's good to have a helper turn the wrench while you keep the socket on the bolt.
9. remove the trans. Be careful that it separates straight out without bending/stressing the input shaft. Note that there are 2 sleeves that act like alignment dowels on either side (the 2 larger hex head bolts). Make sure they're there when putting it back together.
10. remove the pressure plate & disk
11. remove the flywheel bolts. One of them also has an alignment sleeve, make sure it goes back in.
12. The pilot bearing comes out by hammering soft bread or playdough thru the center hole with a wooden dowel & hammer. Make sure you put a new pilot bearing in
13. good time to replace the rear main seal
14. ditto for the trans input shaft seal
15. the throw-out bearing simply pulls off
15. undo the spring clip that holds the throw-out fork
16. replace the plastic pivot dammit that the throw-out fork registers on
Some clutch kits come with a cheapie plastic pilot tool for lining up the new clutch disk, don't try to put it back together without using some sort of precision alignment of the new disk before tightening the pressure plate bolts.
Installation reverse of above steps. What else? New guibo: take note that there are arrows molded into the rubber on the guibo that point to the respective ears on the output shaft & driveshaft. If you clock it a hole off, it will greatly shorten the life of the new guibo. Turn the nut & not the bolt so you don't tear out the metal sleeve. That's pretty much it in a nutshell. Reference Bentleys to elaborate on any of the above.