I see the subwoofer is a 3 ohm stable. I don't really have cash to cough up for 2 1000.1's, but I see that JL used to carry the A1800 which I can get for considerably cheaper...issue is, it only is stable at 2 ohm's.
you can run one 12w7 on a 2ohm amp because it's a 3ohm speaker. why don't you just use one 1000/1 and see how it sounds. if it's not loud enough then add the second 1000/1 at a later date. i can almost bet, you will be VERY PLEASED with two 12w7's powered by one 1000/1.