I was looking to make a similar move recently, the Fitness First clubs were looking for self employed therapists in our area, couple of things to watch out for, i thought they had 1 treatment room, but they were actually looking to fill a few in each club, i would just double check that you would get the monopoly on the treatments you offer.
also, they talked alot about the recruiting members promotion they do and said how the therapist would go too, so would you have to do that, also would you have to advertise them on your independant advertising.
Hth, one more thing, write your list of questions to take with you, i know what i'm like, step into a meeting and mind goes blank!!
xx