I am looking for guidance on which is the best path forward to solve my engine problem. My donor is a 2004 sti. Unfortunately, the motor is toast. Including a cracked head and case.

Which is likely to give me the most bang for the buck:
1) Rebuild the existing 2004 sti motor, add accessport to current ECU, and buy an AWIC;
2) Buy a low mileage newer (sti?) 2.5L motor, replace ECU, and buy an AWIC; or
3) Buy a low mileage 3.0/3.6, replace ECU, and no AWIC (can add turbo later down the road).

I plan to buy a wiring harness from iWire or Wayne for any of the paths above. I’ve never been agreeable to dieting of any kind.

As for performance objectives, it’s a street car. I think I would like power approaching 300 whp. Drivability matters. There is value in a smooth torque curve that offsets the overall horsepower needs.

Any thoughts on what might be the most cost effective or most value for dollars spent option in my case?

Jeff