Being that you are trying to go during the highest of high season, you should just book and hope for the best. Negril Escape always has top notch performers so chances are there will be a great act there when you are there. But to hold off booking in Negril until Fall for the high season you might find yourself shut out of many places - and you seem to be pretty certain of the type of place where you want to stay. Book your trip, worry about seeing a show later. NE announces its line-up sooner than any other venue - and even then that line-up is filled with "tentatives". That's just the way it goes in the music world in Jamaica. Just gotta roll with it.