In the Structural Steel world, NACE and SSPC are joining forces, the AISC(American Institute of Steel Construction) has worked to recognize these paint standards and have adopted a Special Paint Endorcement for the fabricators who hold an AISC certification and want to paint their own work and be recognized as a Certified Paint shop. I didn't attend the SSPC classes so I can't speak for the expertise that you may find there, but the instructors who taught my NACE class had certification numbers in the double digits(In other words, they have been at this for a long time. They have been there and have done that, most have had or are currently running paint inspection programs of their own and teach on the side.
Best wishes in your search, keep us posted how you are making out with this.