Budget- Larger LCD, but you have the same problem I have, when LCD went from 4:3 to widescreen.. 19" are the biggest of the old 4:3, yes there where 24's, but they are HARD to find as they have not been made in years. SO upgrading a LCD will be hard. You could spice it up with some art around the Bezel. Some cheap poster board at the local craft store. One of the many POSTER programs that use traditional ink jet printers.. easy to make cheap artwork for bezel. yes it will have to be glued together, but black background no light under it. SHould look fine.
Side ART- tricky as it looks like that quite a rough surface. A electric sander isnt to expensive if you have a cheap tool store. if you can get it sanded smooth thre are several options for side art (chek the art forums here).
agree with others the Bezel is small, that should be easy to expand.
and yes Building a new cab would be the way to go, but budget and time and skill are all something to consider.