They are essentially the same unit. Bama uses the SCT unit and loads their own custom tunes on it for ur rig. U do have the option of just buying a SCT unit and it will let u change certain things by urself...ie, tire size, gear ratio, basic performance changes, afr i think, and so on. No real reason to do this. This was the common way long ago before custom tunes came to be.
Shoot an email to the AM or Bama team for more specifics if ur curious. Hope this clears things up a bit.