Replacing a broken window regulator - Do I need a new motor as well?

If it is what has seemed to become a standard, it is a cable driven regulator and the cable drive is what failed. Most of these, especially O.E. Come with motor. If you inquire at purchase thety should be able to tell you. In either case, I would think that there should be no re-engineering of the unit to prevent your existing motor from being installed if need be.