Most kicker amps are only 2 ohm stable, so if you you are going to use 1 sub, then you would want a dual 4 ohm voice coil to wire them in parallel to pull a 2 ohm load on the amp maximizing its power output.
But i will say this, if you are wanting decent sound quality, I would seriously consider somthing other than the L7. They have never had great sound quality, and have been built more for the SPL use. Go with a round cone. Something like the 42CWQ154, the same as the L7, but using a round cone.