What are your goals? Those program are just going to teach techniques which are very hard if not impossible to generalize once he is done. This hard for a 12 year old or an adult. And then what happens when the techniques don’t work. How will your son feel? How will you feel? I’d put your money towards an SLP who really gets the ins and outs of stuttering. And look into groups like the National Stuttering Association and Friends: the Association of Young People who Stutter. Edited to add that I am an SLP and a person who stutters.