They are all going to sound good but the Solo X 12's will hands down hit the hardest. You can never go wrong with any of the L7 series but it also depends on what kind of vehicle you are planning to put this in. With the solo X's you can run 2 of the KX2500.1 amps. My friend has close to the same setup and is in love with it. With this much power you should probably invest in some thick wire, probably around 2 or 4 guage and probably a capacitor so your battery doesnt take a beating. All of this will get pretty pricey though.
Good Luck!
