Car Stereos: need a sub for my amp, rms power, car amplifier

Question
i have the 1500W 2-Channel Class A/B Crypt Series Car Amplifier and want 1 sub. i don't know how to find a compatible sub.
amp specs=
   *   RMS Power Range : 500-650 Watts
   * Number Of Channels: 2
   * Maximum Power: 1500 Watts
   * Frequency response: 10-20000 Hz
   * Built In Crossovers: Yes
   * Channel Separation: Yes


Answer
Steve, there are many subs that can handle that much power, and much more.  Many different brands out there will do the job perfectly.  If you are solely looking for dbl, I would suggest looking into sub drivers.  If you want a decent sounding sub, I would suggest JL Audio.  Hope this helps, Scott