I have one 15" Kicker L7 and i love it. It hits hard and very clean. The amp will make you love it or hate it. For a while I had an audiobahn 1800 watt amp powering it and it sounded good until I cranked it up and it distorted. Also with the audiobahn it would always be too loud on mids and wherever i didnt want that much bass. After that amp blew less than a month I bought a Rockford Fosgate amp putting out 2100 watts. This amp is far better than the audiobahn. The bass is very clean and will never distort. The db. knob is always great too so you dont have to keep going in the trunk to re-adjust the bass.
Also with the L7 i could never find a ported box anywhere so I had to make my own off the specs on the website. There are 2 types, the vented compact(which i built) and the vented spl/deep bass. Mine being 3 cubic feet and the other one 6.
But anyways if you decided to go with the L7 I have a brand new one still in the box as well as the drawings for the ported box.