Since I am more a software developer, I was thinking of outputting the data gathered by the arduino to a pc. Once you have the data on a pc, you can do basically do whatever you want with it. However preference still goes to a more 'hardware visualization'.
Have you thought about the TVOut library/hardware? You could output to a huge TV, and let it deal with the power needs.
Of course, a huge, power-hungry display seems contrary to the spirit of your project.