[Scott Fraser]

1) "tonally neutral" mic preamps
2) 8 channels
3) ADAT lightpipe output (44.1, 48K @ 24 bit)
4) 1 RU (if possible?)
Short list:
Mackie Onyx 800R
Focusrite OctoPre
Presonus Digimax

Add to the list the MOTU 8Pre. "Tonally neutral" covers a bit of
territory but if you can get by with something less than an 8 channel
Millennia, the MOTU mic pre is pretty much non-colored, though
certainly not an audiophile level device. The price sure is right.

Scott Fraser