Best Excursions for the money/Ocho Rios?

I am coming in June with 30-40 people for my wedding....I want to take everyone on some excursion and want it to not leave me broke!! Any suggestions? I was thinking of a "booze cruise to Dunn's River or something. We also want to zipline, white water raft or something too. Any advice on who to go through?? Thanks so much for your time.