Black one is nicer since it has the sport package, but then again it doesn't have the premium package (no leather)....but BOTH are way overpriced!
Have you looked on this board for cars? There are some very nice cars at great prices!
Here is a 335i coupe for $28.5k with less miles than the 2 328's you are looking at.
Nonetheless, keep looking...at that price range you should find a fully loaded (with premium, sport, nav,) and lower mileage 328i. Or, you can find a base 335i for that price.
Best of luck!