Okay - (I had to go back to your intro post to make sure I remembered reading it correctly)
Your existing lens is about the same as 28-90mm on a 35mm film camera. ; Which is what I would say is the bare minimum for wide angle for Illuminations. ; (Personally I would go wider, but that's just me)
It's perfectly fine for Wishes. ; This one from Music Magic & Mayhem, taken from around Casey's Corner, was at 45.5mm equivalent:
So the lens you have now would be fine for fireworks. ; The three options I can see would be to get:
1)the 18-180mm lens (36-360mm equivalent); probably the pricest of the options but you wouldn't need to change lenses that often.
2)the 40-150mm, which would be 80-300mm equivalent.
3)the 70-300mm, which would be 140-600mm equivalent. ; This one would be perfect for taking pictures at Animal Kingdom, but you lose a lot of flexability along with the 90-140mm range unless you get a third lens.
Also, just make sure you get a good tripod and a remote shutter release. ; (check the manual for which one is compatible with your model, not sure if the current model is)