Most of these are not cheap though, I will give you another option at then end that if you are looking to do more on a budget maybe something for you to look into.

Escient: makes one of the more affordable media servers. It works pretty well not to difficult to setup, as will all of them they do require internet access to download cover art and update media information..

Kaleidescape: is making the best system right now but is very expensive. Its a amazing system

The other two lower price options are Sony and a few others make mulit disc cd and dvd players that you just incorporate into your system.

Lastly you can build a custom media server (if your good at building pc’s or know someone that is)
You can build it with as much storage are you would need and add to it as your library increases, everything is stored on hard drives no need to handle dvd’s or cd’s again once they are burned onto your media server. They quality of playback is determined by the quality of video card you use so if you are doing 1080p you will need a very good video card so keep that in mind.

I’m including links to all these options including how to build a media server if that is something you might be able to do with some help.

Kevin
35 years hi-end audio video specialist
References :
http://www.kaleidescape.com/
http://www.escient.com/
http://www.google.com/products/catalog?hl=en&q=multi+disc+dvd+players&um=1&ie=UTF-8&cid=3349602005672467774&ei=EDjwS-e4K4rYNr_r4N8P&sa=X&oi=product_catalog_result&ct=result&resnum=1&ved=0CDYQ8wIwAA#
http://www.macworld.com/article/146120/2010/02/unraid_server.html