amps/subs question

[greasemonkey]

All the stereo talk recently has gotten me thinking about my own system. I don't want a $2000 stereo system but I am looking to seriously upgrade mine. I am definitely ditching the Custom Autosound pods and shallow Pioneers and I will be making my own pods with a pair of Infinity 6.5s (like the ones Chevydude has, they sound like a good speaker overall). Eventually, I would like to boost it some more with an amp and a couple subwoofers. What would be a good sub and amp to put in the truck to make it thump? It just kind of rattles now. My Pioneer headunit already has the amp hookups, I would just need to route all the cables. I don't have a ton of room under the seat, I was thinking I could get a couple of 8" or 10" subs and put one under each seat and the amp in the middle. I would like good clear sound and definitely kickin bass.. Any suggestions?
Thanks,
John