Maybe should you first considere how you use your car (and your brakes).
With standard calipers and good pads (IE Mintex 1144), even with tyres that have high grip (ie Yoko 048), you can block the front wheels at high speed.
So, if you upgrade, according to me your goal shouldn't be "to brake harder".
Having 4 pot calipers (and vented disk if you choose the CC kit) will help to dissipate the heat much better. In other words, if you do some track days and feel that after 15 or 20 rounds your feel that the pedal goes deeper, then you should consider upgrading.
So, according to me, the question could be "do I need to brake longer".
If you need to brake stronger => upgrade your pads (and maybe your tyres)
If you need to have strong brake, longer => ugrade to 4 pod calipers.
My €0,2 (sorry for my English. Good news is that you did not hear my accent 😬)
Edited by - Catastrada on 10 Feb 2007 09:00:58