Non-OEM brake pads only in front

[jackr@internet.kronos.com]

     My V8 needs new front brake pads (non-UFO).  The rears are fine.  If 
     instead of going with OEM pads, I go with Cool Carbons, will the 
     allegely superior performance of these pads mean I need to replace all 
     four corners at once, or can I just replace the fronts and keep the 
     OEM pads in the rear?  It seems if these pads really work better than 
     OEM, I would need to balance the front/rear braking if not replacing 
     all four wheels.  (I don't know how to do that.)
     
     Jack Rich
     90 V8Q
     88 Corvette convertible
     84 4kq