Get componets (tweeters & woofers in one package) for the fronts and ditch the factory tweeters.

Buy a quality amp and you will often get more power then what it is rated at. I just bought a 4x75 watt Alpine that bench tested at 4x100 and I also bought a 1x600 Alpine (sub woofer amp) that bench tested at 655 watts. I know this to be true becaue alpine includes a small index card where the quality control tester fills out the ACTUAL power vs the speced power.

If you buy quality you will get cleaner sound too which is better for the ears and your equipment. I would have quality any day over power if I had to choose one.