I'm starting my TT Conversion on my 96 3k SL in about a week or so. Only thing I have a question with now is the wiring harness. I've heard so many different things and I'm so lost on what to do. Because electrical is not my forté.

Okay so, should I get a 2nd gen VR4 ECU, and a 2nd gen VR4 engine wiring harness? If so can you point me in the direction of where to get one. There are none local to me.
Also if I do get the ECU and Harness there should be no splicing involved correct? And no tune is needed?

This may also play a big role in all of this. My car, as an SL, is Cali Spec. So should the ECU I get be also Cali Spec? Or can I buy a fed spec harness and fed ECU?