try running a either a rockford fosgate bd1500.1 or and mmats d class amp to it. depending on the ohm load that the speakers will be running at, will determin which mmats amp to buy.
if you have the money, i'd say try a JL Audio 1000/1, i've heard some really nice things about their amps, and the crossover is supposed to superb, being 24db/octave, and i think it's continuously variable.