The clutch pedal self adjusts as the clutch wears. You can adjust the clutch pedal at the master cylinder...if you have a factory service manual, it will show you how to adjust and measure. If the clutch isn't slipping, don't worry about it. Once it starts to slip, start looking at a replacement. The stage 1 exedy clutches are decent, as well as the ACT heavy duty w/full faced organic disc (HDSS). Whatever you get, make sure it's a light pressure plate with a full faced disk. An OEM ITR clutch would hold a little better than the GSR, but not much. The only reason to get an aftermarket clutch would be if you plan on making a decent bit more power than stock, or plan on racing a lot. It will hold up better to repeated abuse.