I did not read the whole thread, but have you seen these yet?
http://www.sureelectronics.net/goods.php?id=1095

32x16 Red/Green LED's gives you three colors.
Very easy SPI interface. I have 3 of these linked together using just 3 SPI control signals and 3 Chip Select Signals.
I have seen other link upto 8 of these boards together. Here are a couple of links.