if you put the full 1000 watts rms to type x's (i think thats what theyre rated at) it will probably be as loud as the L7s or at least close bc technically the L7s are 750 rms each. Go Type X's, but if you're preppin to drop that much coin on subs, get a pair of Digital Designs or some Fi SSd's or Q's. THey'll sound amazing and blow most of alpine's and all of kicker's products away.
cal, a type x will not have more output than an l7. even if you give 1000w to the x and only 750w to the l7. maybe in an extremely good install. but definately look into better subs cause imo they both suck, especially the l7.
the l7 can take more than 750 because ive street beated with it on over 1k and done comps with 2500 with it my friend is sellin one in a kicker prefab box that hit 140.0
I would say get other subs as well.. As for the L7vsType X... you cant really compare the 2. The X being more of a SQ driver and the Kicker being SPL, and its the technology behind the L7 that makes it more efficient with less power. Id say other subs though.. but if you are sure you want those... if u want loud, get the L7's if you want it almost as loud but sound much cleaner.. the Type X's..