If I were to do something on this these days, I'd just buy a low-end Gumstix board and attach a cheap LCD to the Gumstix's built-in LCD interface.

This would allow a variety of possible connection methods, including serial at up to 800kb/s (the empeg would limit that to less), ethernet, and bluetooth.

And with a real Linux computer (the Gumstix) controlling the LCD, it could do grayscale/colour and should handle complex visuals just fine. Not to mention all of those extra I/O pins and interfaces for other empeg add-ons to take advantage of.

Cheers