Just throwing in my two cents..
I'd go with Dragon Pulse. You mentioned that Boom Burst has 100 Accuracy and no negative side effects, but Dragon Pulse has the same attributes. Besides, you can't hit Ghosts with Boom Burst, and 140 power vs 120 power isn't that much of a difference.
Enoch pointed out that you can't hit Fairys with Dragon Pulse, but in my opinion, Air Slash isn't a bad attack at all with STAB. So I suggest you use Dragon Pulse, and Air Slash to attack Fairys.