Here is what I put in:
Pioneer DEH-3400UB Headunit
Rockford Fosgate PRIME Series R250-4 4 channel Amplifier
Rockford Fosgate PRIME Series 6.5" Coaxial Speakers (Rear)
Rockford Fosgate PUNCH Series 6.5" Coaxial Speakers (Front)
Customer Purchased all the gear and I put everything in just in time for bed time :)
Install went good, speakers weren't too difficult to install (with the help of some spacers).
Overall, this upgrade was perfect for what the customer AND his daughter wanted.
With the amp under the passenger front seat, and the settings set just right, the driver can crank the music without worrying if they'll blow the speakers or not.
I foresee another amp and sub addition down the road though :) :)