if you've got the budget for nice sub amps and subs, then look into some Alpine thin type r's 10s or 12s, or the JL 13" 13TW5 is a great options as well. All of these subs want upwards of 600w each.
http://www.hertzaudiovideo.com/Doc/hertz_sv250_tech.pdf or you can look something like that.Depends on what you're looking for and the budget you're willing to reach
