Redsfan you have a lot to learn about car audio if you think that Kick is some of the hardest hitting.
Here is your homework, look into the following sub, RE AUDIO ( XXX, MX and SX lines) JL Audio W7, Orion HCCA, FI Audio, Elemental Designs, Digital Designs. All of the mentioned will blow Kicker out of the water.
For your interior speaker look into Elemental Designs Audio e9.65i, $225 a set and very much well worth the money.
Sub, look into the HCCA line from Orion. Does not cost way too much, but it is certainly not cheap.
The amp for the interior speakers Elemental Designs makes a 4 channel amp or look into the Kicker 08ZX350.4.
Amp for the HCCA Power Acoustik BAMF series, since all it is doing is producing bass, clarity is not a priority.
Stereo, depends on what you want. If you want something that play DVD's then look into Kenwood or Pioneer, if you looking for something without DVD playback and just music then look into ALpine or Eclipse.