500 cd's sound like something you could rip. I would go that route. Either buy a server that can rip directly or buy a small computer (if you don't have one) for ripping and a server for playing music. Add a good dac if that is not built into the server.
If you don't want to rip everything then I would recommend a CDP + dac.
If you don't want to rip everything then I would recommend a CDP + dac.