Talk with Amanda (amanda&gabe2008 ) - she had originally booked Riu Negril & changed to Ocho Rios, so she probably has lots of Negril info for you.
I chose Ocho Rios because of the excursions available...at Ocho Rios, you can do a ZIp Line Canopy TOur, ATV tour, hiking, mountain biking, waterfalls, horseback riding, swim with dolphins, etc - lots more options than Negril.
I booked our dinner at one of the restaurants at no extra charge, though it will be semi-private. I also booked the disco, which will be completely private from 9-11 for our reception.