I'm sure the black with chrome would look better than the red highlight, but of the options you've noted, I'd go M-Sport black with the beige interior...I say black over grey because you get better contrast with black.
Midnight and Imperial should have been offered on M-Sport instead of Sport-Line. IMHO, the red detailing and the seating (black is ok but the red stitch/pipe is still there) choices in sport line don't fit very well with blue exteriors, while the M-Sport beige interior and burl seems like a nice match for both Midnight and Imperial.
Here's an x1 with midnight over black:
http://e84.xbimmers.com/forums/showthread.php?t=732485