I was pretty impressed with the Sound Storm PSY 1000.2 1000 watt amplifier. I purchase this to use the "full range" amplification in an arduino electronics project I was working on not for a car sub. I tested the audio response with the oscilloscope to make sure it was relatively full range and would meet my requirements for my project. It had very low power consumption when not in use, and very little heat generation when using on the bench top.
I think this would be an outstanding amplifier if you were going to put it in a car, it is very well built and has a good audio response sensitivity.
I would recommend the purchase of this product.