Every youngster and his dog thinks it's easy to bolt on a turbo. It isn't. You need a new, remappable ECU which understands boost (rather than just vacuum), new inlet and exhaust manifold, new injectors, fuel pump, fuel pressure regulator, new exhaust, the turbo itself, several hours on a rolling road setting it up.
Alternatively, the 20v Coupe turbo has all that an can be picked up for less than £600 of your anglitski squids. Remember, the Stilo Abarth had the 2.4 litre version of the 20v motor.
But the best place to start would probably be to get a book on turbocharging and read it.