Your kidding right?
Saddle brown and the dark wood option go GREAT together.
They compliment each other perfect.
Saddle brown with grey would look silly.
And Saddle brown with the aluminum doesn't make sense.
The brown is a warm color which is inviting, aluminum trim is cold and reflective (it adds contrast to black leather interior and that's where it should only be used).
I had both the brown in the 335i coupe and my 335i sedan both with the dark wood trim (and Montego Blue exterior), and got compliments on it like crazy. I also sold both in days, (several interested parties) without ever advertising them.
If you get Saddle Brown interior, the brown wood trim is essential to look balanced and correct in color and mood.