Sorry..
For me a better option would be a V8 1M Coupe
- it's been done in Egypt started with a 118D shell and pretty much changed everything on the car. see vid below
Apparently this can also be done using the DCT box.
In terms of cost, i'm not sure, but would hazard a guess and say £7-£10k for parts. labour could be anything if you're getting someone to do most of the work...