Personally I wouldnt bother with the cordia motor. They are timebombs waiting to explode. Old bits a missin stuff was rubbish from the factory let alone after 20 years. Its different these days, buts thats not the question.

As far as turboing the a12, just chucking on a j-pipe and standard boost, reasonable increase, but unless the motor is up to it, probally not for long.

Turboing the a12 has been covered heaps before. Try the search bar and read some of the older posts to give you a good idea.