[Raceboy]

I don't recommend using some kind of hybrid turbos on aircooled Porsche engines as those create heck of a lot backpressure and thus you will get loads of detonation and no power.
Instead you should use biger turbocharger than you normally would use on similar size watercooled powerplant.
Here's the cracker: why do you think 930 turn out such a laggy (but nevertheless, fun) machine?

And besides, I strongly recommend to twin-plug the heads for boosted car as this reduces the need for advance and you will get more power at the same boost levels.