You can also run the colour coded ECU's, even series 1 ecu's will work, they all use the exact same wiring, HOWEVER if you use series 1 ECU's they will not take readings from the knock sensor, and the igniton module doesnt read from the secondary coolant temperature sender. (not all series 2's have these anyway for some reason??)

By the way ive just traced through the wiring diagrams on both a series 1 & 2 to confirm the wiring compatibility before i posted this