Generally, you want to try to match the specs on the sub with the amp, so say 250 watts sub, and 250 watts amp. I run a 300 watt sub and a amp that is 400 watts at 12.2 volts, which is probably closer to 475 amps when my car is running. I turned the gains down slightly so I can turn up the volume a little more. No clipping, no distortion, and it pounds when I need it to.
In the end, that Kenwood is prolly the best thing you could buy for the money.