Having the intercooler it self won't really work for us. When we designed our intercooler kits for the 335i, we removed the factory lower charge pipe due to the restrictions in the piping and built our own mandrel bent 2.5" diameter lower charge pipe. We also removed the factory c-clips and used a standard style inlet/outlet to ensure we have no leaks at higher boost levels.
If we could get a local guy who wants to bring in his car, I would make them a screaming deal
To be honest, I don't know the factory boost levels of the 335d, but if it's like most diesel cars I imagine it's somewhere between 38-50psi. We can definitely build an intercooler that will support your goals
After talking to the owner yesterday, I think we could make some serious power with the diesel model and a turbo upgrade. haha