Ive had a 12" JL in the back of my car that was rated at 600 watts, i had this in a non-ported box and hooked up to a 600watt audiobahn amplifier, sounded great! wasnt too clever on the real low frequencies but plenty punchy enough,
If your looking for the low frequency shake your car and brain to pieces without spending an arm and a leg then the pioneer TS-W3001D4 is a great choice, i had just one of these hooked up to a lanzar MXA-282 (not the greatest amp i know), and the thing was insane and so crisp!! Cost me £80 second hand off ebay for the sub, amp and a great quality ported box!!
Another nice, cheap and great sounding set-up is the Vibe CBR12 double ported enclosure with 1600watt CBR sub and in-built Blackbox 1 amp (600 watts), ya can pick these up for less than £100 now and they sound fantastic without having to faff about with mounting amp and wiring etc, will run great off just an 8 gauge wiring kit as well!
As for the components id run them off a serperate 4 channel amp, would be nice if you can change the settings from one set of 2 channels to the next (adjust front from back), it'll cost a little more obviously but ive never even thought about running them off my head unit again, massive difference (obviously depending on quality of amp and speakers, mine are top of the range pioneer speakers hooked up to a 200watt pheonix gold amplier)
Hope this helps...
