I would say the LI's would be better. I ran my single LI up against a single 12L7 a couple months ago and had by ear, much better sound and was louder. This was by ear mind you so its not going to garrenty you to be louder. I would deffenetly stick with the LI's over the L7. LI>L7 IMHO
I've been hovering over the IA forums, recently, asking too many questions for my own good. I've seen what IA can do, the numbers, the excursion ****, I've done everything except listen to them. Saying such, I believe that an IA LI 12 would be louder and have better quality than a Kicker L7. Plus there's that deal about price.
As for an LI versus an SE, that I'm not sure about.