I currently have a 2007 Chevy Trailblazer SS. Im looking to install some subs. I used to have 2 powerbass extreme 15's with a 3000w amp in a 2 door chevy blazer. Im not looking for a system to be that loud again Im looking more for good clean bass with some good hit also. I currently have a Kenwood DDX719 7in head unit, rear fold down screen 12in, rear door speakers are polk audio 5.25, stock bose in front doors and dash 3.5. Im looking to upgrade all my speaker, get subs, amp and box. Please give me some suggestions on these components(door and dash speakers,sub, amp). Also should I build a box or buy? I use amazon so If you could supply some links that would be great also.My price range is anywhere from 500-800.