PW and I5 engine question

["Robert B." <robbrauns@bb.eulink.net>]

Hello List:

Sorry if I started a thread on PW, but I've heard that the aftermarket
units for sale over here leave an ugly bulge in the doorpanel. They are
supposed to be better than Audi OEM units, tho. All in all, I thought
that I might be able to use the Audi wiring and switches and motors, but
maybe buy aftermarket regulators. No matter, no one offered me the parts
from a US car.

Now for another serious question:

I want to upgrade my motor from the 136HP I5 to something better. Don't
flame me: Turbos are great, but I also want lots of low end torque and
I'm not sure that I can live with turbo lag everyday...

So, all things being equal (say a budget of $3000), would you:
1. Build a stroker 2.5L motor, P&P the heads? If so, 10 or 20V?
2. Install a 10V turbo? These are not common in Germany and are a 15
year old design.
3. Install a 20V turbo? Lots to change, but powerful motor.
4. Install a supercharger on a NA I5? Is this even possible?
5. Install a Golf GTI motor? (either 16V, G60, or VR6?) I live in
Germany, so I can get the parts I need to install a VW motor into an
Audi, since that's what the factory did!
6. Something I've overlooked?

Just thinking how to make a great car even better.

Kind Regards

Robert in Germany