I can see a lot of 928 with small blocks in the future.
Have you seen what it costs to rebuild a 928 motor?
For the 911 it has to be air cooled for me. Just wouldn't "feel" right any other way.
That flat six has plenty of character and feel.
I can see the logic for using a V8 but owning a 911 isn't about logic.
What about an early 996? That may be worth doing considering how cheap you can pick one up with a broken motor.