High performance clutches?
You dont need a new motor, a clutch bolts onto the motor and fly wheel, they will pull the transmission out and then the bell housing to replace it. If you buy a clutch, you dont need anything else, but if you are basically stock, its not really necessary to spend the extra cash on a high performance clutch. They last just as long, it just depends weather you beat the crap out of your car or not.
As far as the gas pedal, you can replace anything but, its been 8 years since the car was new so see if there is anything to tighten. Its not unusual