different engine/'90 Coupe Q

[Brooks Ellis <brooks@fortnet.org>]

  I was looking at one of these, and was wondering what I could do for 
more power. Last resort, I could NOS it. Turbo - sounds painful and 
expensive for the return; same w/ supercharging. My current thought is 
stuffing a different engine into the 20v bay, or perhaps a 2.5L (+?) kit 
for the original 20v.
  What kind of engine could I stuff into the little compartment? Do you 
think I could get a V8 engine in there? A turbo 10v? I have heard that 
you can put various porsche engines in there - what kind/size/etc? 
.. I assume I would have to replace all of the internals - computer, 
sensors, etc.. but how would the climate control work? I assume it would 
work ok with a Turbo 10v or the V8..but would this be screwed up with a 
porsche engine?

  The engine has ~120k miles on it anyway, so I am thinking that a 
rebuild might be in order anyway, so how about a 2.5L conversion? 
Reliability? Expected power output, HP/Torque?

  last question - do you think that any good Audi shop could do this? 
Would I need to go to an Audi specialist, an engine specialist? What kind 
of price range would I be looking at if I found a donor car/engine say 
from a wreck?

Thanks 6.3 billion,

Brooks