Yea it's a mono amp, but I think Glasswolf meant check out Kicker brand. They do have 4 channel amp. Have you thought of getting 2 smaller amps instead of one 4 channel? You can then put each amp under driver and passenger seats. Just a thought.
Thanks for the help guys. I havent even thought about two small amps, I will look into that angle. I have a friend that has some older Kicker amps and the for the money the work great. Im putting this system in my suburban and Im trying to get a thumpin system and still have space for hauling and everyday family requirements. My PPI 4800 kicks butt, but its about 30" long. Thanks again