The only clothing optional resort in the Dominican Republic is Caliente Caribe is as laid-back or high-energy or Erotic as you wish, depending on the group/time frame you visit. Choose your vacation according to your lifestyle choice.
There is also Cambium which is a little in the central part of DR and a little rustic. They have several casitas or houses for rent at very reasonable rates and a pool and restaurant / bar. Its a live nude community so sounds interesting.