Cruise groups / vacation travel groups

My office has asked for input from us employees on a group activity for next year. We’ve already done picnics, catered dinner dances and the like, so we’re looking for something different. I was thinking of a group cruise that could be organized through a vacation travel group. I’m not sure where to start looking to get costs, information on booking, what is required for a group, or possible destinations. Would there be lower costs since a group is traveling? I think it would be a great chance for everyone to get to know each other. Does anyone have any feedback on a cruise and vacation travel group?