If I'm not mistaken there are 750w rms? if so give at least a 1000 watts to 1200.
I have a 1501d pushing my 2-12 L7s and it beats the hell out of them. If you want them to sound right put them in the right size box. I did'nt at first, I just put them in one of those generic pre-fabs and they just sounded alright. But when put in the proper enclosure, BAMM !!! you can feel it in your bones. Good luck bro.
Just read through these threads I beleive there is one just down from here talking about the cheapest 1500 watt amps are out there. You should get some good ideas there. Good luck.