Anything worth doing is worth doing right.
If you really have your sights set on killing an sti look at it this way.
* AWD and 4WD systems have much more parasitic/drivetrain power reduction due to the increased rotational mass, thus the only place that having AWD benefits in a straight line is the launch.
* I have seen 300+ D series, BUILT from inside out of course, but still , as I said earlier. If its worth doing...
* Your car is much lighter then the STi
As I said, it'll take money, but if you really want to , it is a very realistic outcome.
And about the D series being built by Honda as a performance motor...
That must be why all the R's and (most) of the Si's dont have em.