I went with the SuperBright LED lights. Also try swapping the light sockets so that the that the brake light is on the top. There are other mods that people have done, but this is an easy plug and play mod on the SPF.
LED Brake Light, Turn Light and Tail Light Bulbs | LED Car Bulbs | Super Bright LEDs
Quantity: 2
Product: 1156-RLX3 Luxeon LED bulb $ 23.95 (each)
Options: Red
Quantity: 2
Product: 1157-RLX3 Luxeon LED bulb $ 23.95 (each)
Options: Red 1157
Also, don't replace the front turn signals with the LEDs, because you'll overload the flasher.