You can try getting a used Digimax Presonus 48k. 8ch, ADAT out up to 48khz, 24bit, built in compressor. Line out but no inserts though. Usually goes for $450 on ebay.
You could also run a pair of ART DPS-II units conected by ADAT/TosLink. The units have some interesting lightpipe (ADAT & S/PDIF) patching capabilities and do up to 96 KHz. There are a lot of simultaneous anolog and digital options with this setup.
The Behringer ADA8000 has 8 pre-amps w/ ADAT in/out. It will use either 44.1 or 48khz. Nice pres on it, no compression, nothing fancy...just an easy way to get tracks to ADAT.
Well, a MOTU 896 does have 8 pre's in it, but it's not just a preamp, it's also a firewire interface. Good stuff, but overkill for what it seems you're trying to do.