I think they would look good black. How long have you had the rims? It is very difficult to get a good finish when powder coating old chrome rims, especially if they have seen their fair share of overspray from tire dressing. No matter how much you sand the chrome before you powder coat them the "armor all" will mess up your finish.
I was in your same boat a while back. I initially had the Chrome cobras on my car and wanted to powder coat them black but after learning thatthey might not turn out to good I found this set of black Cobras from OE distributors and if my memory serves me correct they were only about $500. Worth the extra three hundred in my opinion. Plus you can either sell your chrome ones or keep them and switch them back and forth whenever you like.
Also, just an observation what size tires are you running. They don't look very wide. Next set of tires you buy I think it would look a lot better if you went a little wider.