if you're looking for someone to slap on and repaint a new OEM bumper or something of the sort, I recommend Heller Auto Body in Escondido, Ca. My brother used to work there before he went to college, I had some work done on my old camaro and my dad's had some work done on his old RX-7 there and we've had nothing but great service and great paint!
If you're looking for a custom paintjob and someone to throw on an OEM or aftermarket bumper, I recommend Hot Rods & Custom Stuff in Escondido, Ca. They do some excellent work with there paint, and they have done cars that are featured in magazines and they are 100% professional, most of the guys there have been specializing in there job for more than 20 years!
Websites for them are:
Hot Rods & Custom Stuff builds, restores, paints, services and sells parts for classic autos, cars, trucks and street rods. Heller Ford Suzuki Escondido North County San Diego
Hope this helps!!!