Also, I have changed everything except the rears. I have an amp running to the subs and another running to the inside four, but since you have the subs that push the bass, the rears are an accessory. The fronts are more important, then with an amp you can adjust so it gives more power to the fronts, so the rears do not blow. This is the setup I have, and my stock rears have not blown.
Most people do not even have rears, but its all up to you.