I purchased one of the squares some time ago to check out this mesmerizing analog circuit. The reaction by everyone to just one individual square was amazement and a lot of fun. I'm interested in turning it into a more 3D display by placing the circuits on individual boards spaced on a round tube structure that can be walked around. The LEDs will be wired and spaced out on this structure (lots of soldering!). The two biggest needs as I see them are: 1) finding cheap LEDs in bulk, and 2) a suitable power supply. Your input would be greatly appreciated.

You can find cheap LEDs on eBay. The analog circuit requires reasonably well matched LEDs, which you may not get there, so that's a consideration as well. Our web store sells the exact same LEDs that go in the kits in off-the-shelf bags of 640, or larger quantities if you need them. As of today the price is 12.5 cents each in bulk, which is (in my possibly biased opinion) a good price for LEDs of that brightness and quality.

For the power supply, you need 24 V regulated DC power, and at least 200 mA of capacity per panel equivalent. For the cheapest options, look through our surplus sources to find their power supplies:

http://www.evilmadscientist.com/links/index.php?category=Surplus+Electronics