Cool local places to find fireworks:

Phantom Fireworks
2822 Forest Hill Blvd.
West Palm Beach, FL 33406
561/434-9339, Fireworks.com
What you'll find:
Black Cat items
rockets
missiles
aerials
helicopters, planes and UFOs

Donny Aaron's Arsenal of Fireworks 8110 Glades Road Boca Raton, FL 33434-4004 561/451-1113, Donnyaaronsfireworks.com
This place is great because it's usually buy-one-get-one-free.
What you'll find:
Mortars / Reloadables
Roman Candles
Aerials / Cakes
Fountains / Sparklers
Rockets
Black Cat Gold