The detangler looks like it would go a long way to solving my problem, but I think what I want to do is almost too basic for that.
I need to feed two digital outs simultaneously (one for my analog insert chain, one for monitoring) -- a card either of those suggested above seem both to be on the right track. The catch is that in my current arrangement, my DAW has no standard PCI slots left and lives in a machine room. I'm wondering if I can get away with using something external, say a pair of MOTU 828's or Mbox's (thus can run firewire cables to my desk instead of long aes/ebu lines.) Keeping in mind this is JUST for the digital i/o, I'm not touching their onboard converters at all (myteks feed the in and out of the insert line, hoping to put a benchmark dac-1 in for monitoring.)
This is probably me being shortsighted, but I don't imagine needing more than a pair of digital i/o's anytime soon (I do a little bit of outboard digital processing, but right now I run those boxes inline with the analog gear, between the mytek ADC and the DAW.)
Many thanks for your input.