My opinion is that unless the speakers are blown, the head unit is the first thing that should be replaced in a stereo system. And w/$275 to spend, you can get a pretty good unit. I would recommend Alpine, Kenwood, the JVC DigiFine head units are pretty sweet too. Just shop around, play w/some of them, see how easy they are to use, get familiar w/the different features and make sure to get something that gives you flexibility. Meaning, don't get the Sony head unit w/1 set of rca's that costs $175, instead get the $250 Sony w/3 sets of rca's, built in eq, crossover, and fold down face. That way if you plan on building a system w/more than one amp, you won't be restricted by the single set of rca's on the deck that saved you some $$$.