To spray or not to spray...??

I currently have the style 135 MSport 10-twin-spoke rims on my black Z4 coupe. I stumbled across some pic's of these rims sprayed (almost) black, similar to the M3 Competition pack rims. I'm wondering whether to get it done on mine, or leave it stock silver. Your thoughts on the black-on-black setup? and about how much would it cost to get them properly sprayed? Any good rim shops you guys recommend?

Thanks in advance!