The base clutch is lighter than the one in the S. I can tell the difference from my short test drives of both cars.I read that too, and it caught my eye. The clutch on my 993 was very heavy. The clutch on my Cayman S is much better, but still feels a bit heavy for my taste.
I drove someone else's Cayman, and their clutch was much lighter than mine. His car was a base Cayman with a 5-speed.
There is considerable variation between individual cars. Some 993 owners reported heavy clutches, some didn't. My Cayman S was heavier than the Cayman I drove. I think I've only seen one report that Gen 2 Cayman's have a lighter clutch, from someone who drove a Gen 1 and Gen 2 back to back. I don't think we have enough information to know if all Gen 2's have lighter clutches than all Gen 1's. Perhaps the Gen 1 he drove was old and had some wear on the clutch, or perhaps it was just individual car variation.
I'd be surprised if you could put the clutch parts from a Gen 2 (clutch, pressure plate, etc) into your Gen 1. An easy first step to check this out would be to download the parts catalog PDF for both cars and check to see if the part numbers are the same.