THe 581 ecus are not immobilized, the later v9 STI ones are almost all immobilized and it has been found the V9-spec C ECUs are not immobilized. I run a 581 ecu on my v9 spec-c swap but I use the carberry SD rom, I requested a 581 ECU when I bought my motor because I did not want to risk an immobilizer and have to wait on a new ECU.
In addition spec-C motors and transmissions almost NEVER come with the coolers. They usually just cut the hoses so you are on your own for coolers.
THose RA-R brakes make me feel all tingly.......me want.