Spencer,
Thread took on new life with Strego working on building his oen FlipDots and working a scheme to power them.
Original plan to have self-return with non-powered magmet pull and flip withe electromagnet in on-state did not work. Now adapting to have dual polarity electromagnet (with 2 way current flow).
What'd you do with LEDs? You can get 12,000mcd & more white LEDs on 20mA, hard to believe those would not be bright enough.
http://www.dipmicro.com/store/LED5W for example
Order now & get a discount even.
Run 2 in parallel off 5V output pin with 120 current limit resistor on each for 15mA draw each.
I've read you can lightly sand the lens to diffuse it more too so will not look like pinpoint lights - if I recall you had them pointed sideways anyway towards sidewall reflectors.
I used 3 of these from 12V source in a scoring machine, at <2mA current, and they are bright! Couldn't even face them at higher currents,had to keep dialing them down, and they are 10,000mcd.
http://www.mpja.com/prodinfo.asp?number=17145+OP