This is the usual set up I go for because its cheap and it does exactly what I want (except for the amp - I usually go for an earthquake amp but it was out of stock everywhere)
1x Pioneer GM-D9601 Mono Amp - 24000w max @ 1ohm - 1200wrms @ 1ohm (I'll be running my setup on 1ohm)
2x cheap 12" Pioneer TS-W311D4 subs (4ohm Dual voice coil) (1400w max - 400wrms each)
1x cheap set of pioneer components for the front doors TS-G1605C
1x 4gauge kicker amp wiring kit (their wiring kits are so nice - some of the best wiring I've used)
I have an existing pair of jvc coax 6.5's for the rear doors that I have had sitting around for a while
This will all be running off the factory headunit initially (kenwood unit)