Darin,
I use a "ZOOM" clutch. Reasonably priced and so far has held up very well.
From what I remember, it had carbon ceramic (or something like that) disc material and stronger clamping force. Not sure that it is "light weight" though. I know other 240sx folks who got the Nismo one and they had no better luck with it than a stock setup.
I ordered it through Advance Auto Parts, but I am sure others carry it too. Having said that, obviously I know ZOOM makes one for the S13, so you would to check as to whether they also make one for the S14.
------------------
Tristan Smith
Buffalo's Southwest Cafe
ITA Nissan 240sx #56