Needing some help here on an Amp. Currently I am running a JL HD 900/5 with a JL 12w6 Sub and stock speakers and tweeters on a 2008 Chevy trailblazer. I have decided to go with Hertz hsk 165xl and hcx 165. So my question to you guys is, should I get a 2nd amp? right know my 900/5 overheats real fast. and i was told by one shop to get a 1200/1 amp for my sub and use the 900/5 for all my speakers. but then another shop told me that that was a waste and if im going to keep the 900/5 amp to get a 600/4 and use both. I am new to this and do not know much. What are your opinions/recommendations?