Hi Nikkeemarie, I'm sure someone else with more knowledge will be along shortly like Westmoreland, Ohliz, JamaicaSteve, JohnnyB, etc with more suggestions for you.
Negril has hundreds of accommodation options. Check out this user friendly link: click on maps on the side, then beach, then click on different places.
http://www.negrilonestop.com/
For the rest of your description....RDMB is real close to meeting your criteria.
Make sure you get a Balcony room not Ocean VIEW. This resort is EXCELLENT value for the $.
It's not like there is no beach...it's just that the beach is man made. For most people who have not been to Negril they thought it was just fine.
Nightlife in Negril is abundant...Alfreds, the Jungle, etc.
Negril is 1.5 hours from MoBay a lovely but curvy highway along the shoreline. Enjoy.