Sound quality does not necessarily suffer w/o a preamp. There are many cases where eliminating the preamp and driving the amp directly from the CD player is a noticeable improvement. A couple examples include: Sony XA7ES or Cary 306/200 driving the amp directly. This will also depend on "system synergy" with cables and the amp.
Volume Controls for CD Players
I have heard that there are a few different ways to implement a volume control function. Some have noise problems and others are non-linear at reduced volume settings, from what I've been told. Also, the fidelity may be degraded by the manner in which the remote control functions. Comments? Happy Tunes!