there are several threads providing help and suggestions with this conversion. search function
as for bar'd, if youre talking emissions requirements, as long as the motor is newer than the original motor, runs good and retains its emissions equipment, you shouldnt have much of a problem.
i dont believe the twin turbos fit, but dont take that as written in stone.
also, i believe the car is old enough to register as "classic" (25 years, right?) so you could do that and fore-go any kind of emissions/swap laws that are present right now, as far as i know.
its been done before, and im sure it will be done many a time in the future.