You can buy many different light weight flywheels for Gen 1 today, just check with vendors or Flea-bay. (Fidanca, Clutchmaster, McLeod, Spec to name few you can find in 3 minutes.)
Mine is 17lbs, which is 10lbs lighter than stock. I have about 800lbs TQ, and the stock clutch is fine for 600Hp and that amount of TQ. You can of course overkill anything.