I would highly recommend going to a hydraulic throw out bearing. I did recently and am amazed how much smoother it is to operate. I went with a Tilton bearing and master. I machined a 1/2" 3x6 aluminum bar stock to sit flat on the back of the bellhousing to give the bearing a good surface to mount to. I also moved the stop on the pedal down and to the inboard side to provide a solid stop.
I'm using a quarter master clutch which is pretty stiff, and hydraulic made it so much easier to control (that and I shattered the original clutch fork).