Start looking for a 2000watt amp. You should be able to get one for around $500. Those are some nice subs, try not to skimp on the amp for them.//content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif
Hifonics amps will give you the power you need, for how long who knows. Like I said those are nice subs and usually if you can afford nice subs you can afford nice amps to go with them. I couldnt afford the subs or amps but talk about dead sexy. I think a rule of thumb should be spend the same amount on amp/sub.
if you can't afford to get two good 1000 watt amps (wouldn't go with hifonics unless its a xx series), i would get a kicker zx1500.1 and run it at 1.5 ohms and yol'll get between 1700-2000 watts
that kicker ZX1500.1 is not 1.5 ohm stable, the minimum is 2ohms according to kicker. and i agree, those subs are way too nice to skimp on the amp. are they in a ported box? if so you could perhaps afford to underpower them a little, if its sealed you need to give them all they can handle. why would you buy 2 subs u cant afford an amp to push them with?