Drop a healer, preferably picking the two healers who are consistently top on that fight. The enrage isn't really that tight, but dropping a healer will give you room for error. Your disc priest and his PW: Shield will be most advantageous, but we have also killed it without me there, so it's not mandatory.
Our rogue and mage were able to take almost every single spark. Your rogue can take it with
glyphed Feint. Our mage took the sparks with Blink. The sparks have an animation which begins a second before they explode. So our mage would run to take one, watch the spark, and blink as soon as the animation started. It is a really small window, but it looks easy enough. We had our hunter use Deterrence or rogue Cloak to soak the ones that could not be taken with Blink or Feint.
We had our fury warrior tank the strengths, but your only other melee is an enhance shaman. I think this will work, he just might need a little attention from healers.
Good luck! I really, really love this fight as a healer. It's so much fun!