Not a stellar programmer, but normally when I want a delay at the beginning I'll start by making a var of something like "Should_I_wait" with a value of 1, then
if Should_I_Wait then
delay(5000)
should_i_wait = should_i_wait - 1

Does the php page work when you go it with your browser? The error 500 is a serverside one, and has nothing to do with the arduino

You aren't looking at something that will be very cheap AND robust enough for what you want. Take a look at the LED Coffee table tutorial made by SparkFUn
Basically they took a bunch of RGB LED Matrixes and linked them together. Each one of those matrixes is about $60, so do the math there.

But you can do all sorts of cool and neat things with it, like play pong.

I have an older CrystalFontz CFA-634, I can't post the link yet, but if you go to the crystalfontz website and search for CFA634-TMC-KS you'll see more info. I googled around and found some people had gotten it to work with the arduino, but they didn't go into details, and I'm to new at all this to figure it out on my own. Any ideas?

Thank you!

Thats and awesome project! Lots of great shots too - good job man!

That would work fine, but how will you ensure that only 1 button is pressed at a time, and no one is hitting 2 or more - either by mistake or on purpose?