Well, before I help you out, I'm going to tell you to do more research.

That being said, I have an s14 sr in my s14. I think it's worth the extra money for a few reasons.

1. The motor usually has fewer miles on it.
2. t28 > t25
3. Head port design was changed from s13 sr's for better flow.

The wiring is definitely not plug and play like it is with s13->s13 or s14->s14 swaps. But its not as hard as going s13->s14. I don't feel like the VTC (cvt is a kind of transmission) is that important. if you buy aftermarket cams you lose that anyway.

Edit: I missed something. Yes, the ECU's are obviously different b/c they use different mafs and therefore different electrical signals.

Hope it helps. I apologize if I presented any misinformation.