You're making one serious deck on the first try. I really like seeing this thread move, as I have populated and tested my preliminary set up of 8in 8out with AES interfaces. Of course they don't really do anything since there is no clocking yet. I did a quick hack attempt at clocking with my RME HDSP, but I'm ashamed to even mention it now. And of course it didn't work, and at least I didn't break my soundcard!
One question, these mainboards seem to be for DAC and AESin boards only (perhaps AES out, too), but how are the ADC longer/thinner boards accommodated?