I think Pioneer is pretty versatile. With metal/indy music it is very clear and I think it sounds good. Then with dance/techo, Fresh FM for example, the bass is pretty good for just two 6" and two 6x9", alot of my mates thought I had a sub lol. I have no idea about amps and stuff though so I usually ask my mate for advice.
He had a mad set-up in his old Exa, with a mix of a few brands, Kenwood dvd head unit, Clarion speakers, Cadence sub, can't remember what amps.
He rates Clarion pretty highly and after sitting in his car one night I can say they're crystal clear.
Cheers, Ben.