Man, I love your current 22" wheels. They are absolutely stunning. If you must change them however, the 640R's are the way to go. I love the Style 168 and in 20" will surely look even better and the price from LSW&T is excellent but your X5 is so modded that it demands aftermarket wheels with some real pop. Those 640's should do the trick.
Out of pure fantasy, please PM me what you want for those big ol' 22's.