I have the UUC/Wilwood kit and you can't use the OEM sensor. The pedal feels much better over OEM but I can't say that alone justifies the cost. You can get the UUC front wheel only kit for about $1k.
If you do go with UUC, I'd get the 6 piston fr/4 piston rr with the slotted rotors. If you want drilled one, buy them from Tischer. The added cost of getting the drilled upgrade is more than just buying the rotors from Tischer. Keep in mind that you go with the OEM drilled rotors, you'll want to paint the hat and inner part of the rotor with some black hi-temp paint.