kx was my 1st choice, but i heard a setup today that had 3 of the new L7's and 2 kx 1200.1's strapped. DROOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOL.
was so unbelieveably loud, nearly as loud as my buddies 2x 15" L7's in a 12 cube ported box. and they were sealed.. Wish i had some pics of the install, my cousin's shop did it.. 3x optima Yeller Tops, 0 ga everywhere, and a custom mdf/glass box.. all in the back of an older body style grand cherokee.. god that was an awesome install.. subs sounded really friggen good too (hit DEEEP).
sooo.. basically imo you don't need more than 1kw on 12L7, id prolly go w/ 1500 on a 15... but 1000 is just about perfect for the 12.