i really don't think you can go wrong with exedy. they have a solid overall reputation across almost all automotive forums that have exedy as an option. prices arn't cheap, but arn't unreasonable considering the good quality of their parts in general. I've driven a s13 once breifly that had either an exedy st.1 or st.2 (i forget exactly which) and it felt very close to oem. i really liked it.
never actually owned a car with an exedy before but i do have act street clutch on my crx and a more aggressive 6-puck on my 240. both also have a lightweight chromoly flywheels. while it may not be an entirely relevant comparo, the act on my crx works excellent! it's easy to engage, but gives a slightly more firm clutch pedal feel. very streetable and fun to use!
The 6-puck act on my 240, however, has not been so enjoyable. the engagement point is pretty difficult to master, and grabs very abruptly. its just very difficult to predict and master. I always have to be super-conservative when releasing the clutch to engage. its horrible for daily driving imo, and prob will be a bit scary for track driving (difficult to drive smooth). I'm really looking to replace this clutch with an exedy hyper-single, should the funds become avail in the not so near future.
I also read somewhere that the aftermarket clutch for the 300zx applications may be worth looking into. I've heard they can handle a lot more torque compared to the corresponding 240sx apps, but don't quote me on it. I haven't really done any research on that (no reason to right now), but i do think it may be worth checking out. well that's my uneducated observations anyways!