I have a 99 Accord coupe that I am looking to upgrade a little. The stock head won't play burned cd's so I'm upgrading that with a Pioneer P4600MP. I have 6.5's in the front and 6x9 speakers in the back. Would the Infinity Kappas be a good choice to improve my situation--and will it match up well with the head if I don't have an amp? I was also looking at Polk speakers--any preference? Any help would be great as I obviously don't have a clue what I'm doing (and unfortunately don't have unlimited cash!) Thanks alot.