Looking over the thread and then coming to the part where it says all of this extensive work just to make plugs changes easier? but what about the massive box of aluminium where the turbo would go anyway, not to mention the heat transfer from the wrapped headers. Have you thought about sorting some sort of an intake for the turbo, where its positioned it will suck a lot of hot air and then heat it even more has it get sent up the pipe to the engine bay, in all honesty you should consider making your cooler pipe from stainless or alloy, being under the car you wont want it to rust and allow for foreigners getting into the engine.
Lag is going to be your best friend, when the turbo comes on you wont have much rev range left to play with being auto that will help keep the boost up. Also what are the cam specs? something with a higher LSA and big exhaust will help it get along. I really do think for the dramas to bit had on the dyno the spark plug changing issue would be worth it.
