I would actually recommend powder coating them since they will last longer, but if you are looking to paint them, then just google body shops around your area they should be able to paint/powdercoat your wheels. However, if you wanna save money on painting then I say do it yourself, they come out just as good if you do it right, check my DIY on how to paint your wheels, hope it helps!
DIY-Painting Wheels and Brake Calipers!