I put in a 6 spring clutch after my crapped out 4 spring unit did its handgrenade impression. Since the old unit was in such poor shape I can't say if the new one would feel any better but my impression of the 6 spring was nearly identical to that of the 4 spring unit.
My $.02? Since you aren't going to track the car, put in the nearly new 4 spring clutch. I'm willing to bet that you can't tell enough of a difference for it to matter. At least you'll be back on the road and can apply the $120 or so to some other worthy project on the car.
