Best speakers, sub/amp to work with factory head unit?

[FlipTrac_511]

If I replace the sub/amp unit (04 Audiophile) with aftermarket ones (using CWells' 8" enclosure) what would be the most practical amp I could get? I will not be replacing the factory head unit so it'd be pointless to pair it with a very powerful amp, this much I know. But what amps would be practical in this application? FYI, I will also be replacing the door speakers with, perhaps, Pioneer type-Rs. Are these practical, or overkill unless I replace the head unit?



(edit) I'm quite satisfied with the current setup, but it'd be nice if I can crank it up a bit more without distortion.

 

[FlipTrac_511]

Hmm...turns out one of (edit) Rich Sterns' project write-ups answers a lot of my questions. Still love to hear from others though.