I have the 12 w7 with a 500/1 pushing it and it is more than enough. especially with my boston pro series components. I had the 1000/1 and it was drawing too much power out of my car. you need to get another battery to run that amp, or you could seriously damage something. I would reccomend doing a 12w7 in a ported enclosure and do some components to get more volume up front.
05' 330ci ZHP Sparkling Graphite Metallic