I know if you live near a craft store they sell them there in various sizes and you could get a nameplate done at a trophie shop. As far as online you cuold try looking around at
http://www.usadisplay.net/
http://www.eyewitness.com/gdclinks.html http://www.reflectionsinwood.com/acrylic_display_cases.htm
Thats just a few that I have found.