I just got my first truck and as with most high school kids you have to put a system in it. I'm not interested in anything really expensive and top of the line, just some mid line stuff that sounds good. I have a 2001 chevrolet z-71 extended cab with four doors. I have a few begginer questions about the components. 1. I like alpine head units, but what price range do I need to get into to notice an improvement over the stock unit. I like the alpine 9827. Is this decent? 2. Do aftermarket recievers have better radio reception that my stock unit? 3. Is xm satellite radio night and day better than regular radio? 4. What speakers would you recommend for my car? I dont listen at very loud volumes. I was looking at the Infinity kappa 62.5/63.5i speakers, are these anygood? 5. What kind of sub would be recommended? I dont want to break my windows or be heard from 3 blocks away so I suspect one good sub will suffice my needs. I would prefer some sort of set-up that could go behind or under the rear seat.