I have instructed for Chin (tracquest) when they came to the midwest, I personally feel they ran a really good show. I cant comment on the other groups you have up there, for your neck of the woods. I am a w2w instructor with Midwest council, also have instructed for "hooked on driving" and March of dimes "drive for babies" (scca) .
With Chin, they required (and provided) an inter com system for the instructors, it made a WORLD of difference, so much so that I own my own now, so that when I am with other groups I can use one. Chin tends to error on the side of caution with new people. They want to make sure you are comfortable before letting you "solo". I watched with interest last year when a Guy brought his vette, and told the powers that be that he was to be in the most experienced group, and his wife was to be placed in the intermediate group. The Man really was good enough, but kinda fudged his wife's experience level. She was over whelmed and a bit scared. Mark Hicks (lead man at Chin) asked her if she would like to be moved down and she jumped at the chance. I was her instructor after that. We worked on some basics, and got her really comfortable. Unfortunately her car suffered some engine problems and she had to quit. If this is your first time, Chin will be a great place to start. Im sure some of the other groups are every bit as good as well ;) Let us know what you decide, and how you do!!
Willy@isellmiataparts.com