As far as I know there are two zips in Ocho Rios. The one at Mystic Mountain and Chukka Canopy tour.
Chukka reviews are excellent and everyone seems to love it. Mystic Mountain also had good reviews.
We are going to do Mystic Mountain bobsled and zip. Did the bobsled last year but not the zip.
I hear that to get to Chukka zip it is a bus ride up a very narrow road with no side rails.
Also the begining of the zip is a 15 minute walk which is pretty muddy so expect to get your shoes and legs alittle muddy.
I'll do any zipline but I'm not riding up a mountain on a narrow road with no side rails....
Both Mystic and Chukka have websites you can look into.
Enjoy whichever you choose!! 8)