Just because they don't specifically refer to themselves as "NH" on their business card doesn't mean they don't use the same types of methods. And advertising themselves as a NH trainer does not mean that they actually are.
Really, NH is more of an advertising jingle these days, and apparently it is also justification for seriously jacking up the prices on very basic items and selling DVD sets that may or may not actually help answer your questions. That style of marketing seems to have worked for some trainers, so others are trying to cash in on it, too.
Think about what kind of training program you are interested in, and what your short and long-term goals are for the horse. Do you want a trainer who will work with the horse on his own, or one who will work with you while you work with the horse? If you want to eventually ride your horse, will you just do pleasure/trail riding or do you want to compete?
Then, just shop around. Talk to your vet, farrier, people at the feed store, or contact the Standardbred adoption organization to see if they can offer recommendations.
In the meantime, your boy is still settling in. He's in a new place, surrounded by new people and new horses, so it's understandable that he'd be a little on-edge. Just enjoy some one-on-one time together, take him for some hand-walks and spend time grooming. If he needs a refresher course in basic ground manners, you can work on that, too. That way, when you do find a trainer and begin "officially" working with him, you'll have a better idea of your horse's temperament and can be prepared to ask the trainer more detailed questions.