I am looking to install new speakers into my car, along with a 4-channel amp. I was looking around and my two personal favorites are Alpine and Infinity. The Alpines though, have lower power handling (rms) and also have a lower sensitivity rating compared to the infinities. Btw I am looking at the Type-R's compared to the KAPPA's. Does this mean that I will be able to get better sound out of the Infinity's or are the figures even related to SQ. Secondly, I was thinking about putting two sets of component speakers in my car. One in the front (stock location) and on in the back. I think this would make the sound alot better, tell me what you think. Also any amp suggestions would be nice.