Your choice...
$75-$100 per wheel to have them powdercoated. Powdercoat chips pretty easily in my experience, especially if you spend much time offroad. There are several manufacturers of wheels out there that you can just buy a new set of black wheels with more width and aggressive offset for around $400-$500. That alone makes powder coating a waste of money and time.
$6 a can (probably take 2 cans) for plasti-dip. This is hands down my recommendation. If you take your time to clean the wheels and apply the dip properly, it will stay on indefinitely. The rubber nature of it resists chipping/tearing greatly. And if it does chip/tear, you have the option of peeling it all off to re-apply a clean coat(s) or it is very easy to repair.