$300 Front

$0 rear- keep current pioneers

$235 Sub and box

$220 5 channel amp

$60 wire kit

$160 sound deadening

If you look around hard enough, you could save some money buying welding wire vs a amplifier kit, but probably not much after inline fuses and spade connectors and such.

Front components are a plus, yes.

Rear, leave alone unless there is something wrong with the ones you have

A million ways to go on amps, but I went for simplicity with a single amplifier doing everything. I would bridge channels 1-4 into your front components and run the rears off the deck.

Dayton UM is my fav metal sub of all time! Diggs really deep for a sealed sub, and never sounds sloppy.

Dynamat is a big yes, it's really the only way to get that tight mid-bass out of a leaky door "speaker box", floors cut road noise, rear deck can help out midbass for the rear. Trunk kills rattle, etc.