Car audio system ohm question.?

Hi, I am planning on paring up a Rockford Fosgate T5001-bd monoblock amp with a pair of kicker 08 L5 12's. I just want to know what is the difference between 2 ohm and 4 ohm? And also it is a dual voice coil. Every system has a model number and the model for the 2 ohm is 08DS12L52 and the 4 ohm is 08DS12L54. Which one would be better? Thank You.