To determine what type of trainer, instructor, or clinician will benefit you and your horse, you will need to determine what type of riding you will be doing.
If you had a Tennessee Walker, you probably wouldn't pick a "show" Tennessee Walker trainer if you're going to trail ride, since the end results of the two types of training are almost diametrically opposed. The same with Icelandic Horses, you probably won't want, need, or benefit from a trainer, instructor, or clinician who rides competitions. Conversely, they probably do not know what type of training is needed for a horse to trail ride in America.
With shows and competitions, there is a different mind-set of the people in regard to horses.