First off I agree with the idea about the body shop...I don't know where you are located but there is shop by my house that does paint body conversions and the whole bit. They would be able to tell you

1. If the swap is worth your time and money
2. If its possible
3. How much for the front end and installation

From there you might be able to make an decision if you want to do it.

With this job though, you might need to actually get a new paint job, on that note i wouldn't suggest doing this to an Audi...(A new one anyway)...You figure they are doing BODYWORK therefore that requires sanding and the whole bit and if you wanted the same kind of paint its definately going to be expensive...But i think the whole idea to me is to keep your car looking as if it came from the factory that way...If this comes out being a clean and neat install then i take my hat off to you...I personally like the front bumper that you want to install. But then again it doesn't matter what i think either...