You have to find one of two amps....
1.) A amp with a rating of 750 - 1000 watts at 4 ohms
OR
2.) An amp with a rating of 750 - 1000 watts at 1 ohm
Thats the only two amps that will properly work in this situation.
If money isnt an issue i would say get another L7 (dual 2 ohm) and wire them together in a way to get a 2 ohm load adn get the Kicker 750 mono amp. Thats the setup my brother has and his system rattles your eyes