Is there any banquet halls /rec centres that could hold over 1000 people? Any casinos that have this type of room? I hear Sosua has a room at their Casino, not sure what it holds, any feedback appreciated.
As "windguy" stated, the convention center on the second floor above the coral reef casino in front of the Sosua bay hotel (now Bellamar) is probably your best bet. It is certainly the largest venue of this type in Sosua or Cabarete. According to management, they have a "seating capacity" of 800. Depending on your specific needs it could be more, e.g. utilizing the stage for seating, etc. Below is a photo taken last year when the Ahnvee Resort had an "employment fair" to give you a general idea. The stage that I mentioned is cut off in this photo.