Budget CD / DVD or D/A solution

I have a moderate family room system consisting of Cary 40M Signature monoblocks, Red Rose R3 speakers and Preeminence Reference 1 passive pre-amp. My source components are the problem (with the exception of the tuner which is a Magnan Dynalab Ft-11). I currently have a Pioneer DV 343 for CD and DVD playback. I need one unit for DVD and single CD playback (I only have one available input for this application). My first priority is good sounding CD playback. I'm not very concerned about DVD audio or picture quality--it just has to be able to do that. I would like to spend around $500 (more if there's something really great) and I don't mind used equipment (why would I be on this site?) Should I buy a standalone D/A and use it with the Pioneer, or is there a combination player with very respectable CD playback quality?