You've got a lot to learn boy. The power handling rating of a speaker is not a loudness rating. The relationship of power to loudness is indirect. Speaker sensitivity and amplifier output have as much to do with loudness as the power handling capability of a speaker. For example, a 6x9" speaker with a sensitivity of 95db will be noticeably louder at 100 watts than a 6x9" speaker with a 90db sensitivity playing at 150 watts. In fact, at 50 watts output, the 95db speaker will be just as loud as the 90db speaker playing at 100 watts. Not only that, if you're only sitting 2-3 feet from the speakers in your doors, the loudness of either speaker in my example is equivalent to that of a live band at a nightclub. Anything louder could easily damage your hearing after only a few minutes of exposure - the type of damage that cannot be repaired even with a hearing aid. So, besides being a waste of money, your quest for more power is ... let's not pull any punches here ...utterly STUPID.
Forget the ridiculously expensive Infinity Kappa 900 component speakers. In 6x9" speakers, I guarantee that watt-for-watt, the much cheaper Polk DB692's are louder. They play down to a much lower frequency and are a heck of a bang for the buck speaker. At 94db sensitivity and 150w rms power rating they're hard to beat. I don't even use a sub with them. They're not the loudest thing out there, but they're loud enough to seriously hurt your ears if you pump 120w rms into them, and they sound clean. Right now they're only $90 a pair at Sonic Electronix. Best bargain around.