I think that A CPDT is the closest thing you can get to being certified. Unlike in the UK - there is no accredited college degree in canine study for trainers. A PHD in Psychology and animal behavior can lend itself to being a certified behaviorist (much different than a trainer).
The "POSITIVE RE-ENFORCEMENT" motto and era of trainers has caused an influx of people who think they know what they are doing. I call it loly pop and butterfly dog training. And its not reality.
Don't get me wrong - I like the use of clickers and treats etc ...... try to teach a jack Russell to take a bow, spin, hit a target, or jump through your legs with a slip chain and heeling stick - good luck.
Positive re-enforcement works but needs to be balanced with a bit of instruction that sometimes requires positive punishment. I think that being overly PC, the main stream certifications organizations FREAK about any use of force ... to me its just silly.
As I mentioned in my PM - I feel a trainer is only as good as his/her dogs can demonstrate. I am always proud to show clients my dogs and although the illiteracy factor can be frustrating at times - it is nice to be able to teach people how to balance praise and correction, how to read body language, and how to get dogs to ENJOY their work - whatever it may be.
There are lots of organizations which offer "certifications" Some have more detailed programs than others. ABC, NADOI, CPDT, CASI, IAABC are just a few I am familiar with but I am sure there are more.
In the end (IMHO) its the product of a trainer's accomplishments in combination with their training techniques and philosophies that prove his or her worth. GO WATCH whoever you may be interested in. If a trainer does not allow a gallery at his/her classes or some select private session - that says something to me.
How about you just leave Indy with me for two months

LOLOLLOL Just kidding - I think you are smart to do your homework and I belive that since you are so dedicated you SHOULD seek the best person to help you train your own dog! Good Luck Carol!