Please help this noob out with buying an amp

I just bought two speakers and a sub for my regular cab pickup, and I need to know what kind of amp I need. I'm guessing it's a four-channel, but how powerful does it have to be? I'd like to just have one amp for both speakers and subs, but if I need two, then it's no big.

My speakers are Alpine SPS-600 and they are rated at:
# Power Handling:

* Peak: 240 watts
* RMS: 80 watts

My subwoofer is the Rockford Fosgate P3L-S12 which is rated at:
# Power Handling:

* Peak: 800 watts
* RMS: 400 watts

I don't want to spend too much on an amp, just enough to get some decent, quality sound.