nitrous or turbo?

[Festively Jolly]

Well Audifans, the time has come for a power boost in the 1988 Audi 90
FWD.  After it being in the shop i was forced to commute in the 1998
Monte Carlo.  It has what i have been told 180 hp compared to whatever
the Audi has stock (By the way could anyone tell me the bhp measurment
on it?) So now driving the Audi after that power  just seems less
thrilling.  Well I have the money for more power , I just can't figure
out how to spend it.  
   Nitrous I know nothing about.  I don't even know if it would be safe
on the 5 cyl. ANY info on it would be much appreciated.
   Turbo i have heard good things about.  Well at least the Audi turbos
are said to be great but it is doubtful to find one in my town.  Any
aftermarket turbos live up to Audi standards?  I'm looking for a bolt on
operation or close to it.  
   So if any one could be of service i would be much obliged.
THANKS!