I would just get one Memphis 4kd and run it at .5 with a good electrical, 1ohm would work. They'll do rated power + some.
Those Fosgate t20001's will do closer to 25-2600 each, according to the factory benching done at Fosgate when you receive the amps. I've never seen one's birthsheet under 2200, and I've seen them up as high as 2900.
They're enough power for the XXX's.
Still, if you want, you could get away with one Memphis 4k at .5 and get 2k+ to each woofer, just make sure you have that alt and a fewextra batts and you shouldnt have a problem.
Just my .02