I don't think you HAVE to have a new CD player, but I certainly would get one if I was upgrading my stereo. What I would do is decide on a budget for a new stereo setup, and then see what you could get with it. I've always started with a new head unit and worked my way back, finishing with amps and subs. Also, it depends how powerful you want your system...what exactly are you looking for (what kind of music, how much bass, etc)?