Yo Dave! Here's a mildly radical solution. There aren't that many inexpensive digital mixers out there, and increasingly, they are intended to go direct to the computer by USB, but you need S/PDIF. There are some pretty good dual preamps with S/PDIF out, (I use Joemeek twinQ, but that's an $800 or-so box). I was stuck at one time with a similar problem, and I used this:
http://www.8thstreet.com/product.asp?ProductCode=41360&Category=Audio_Processors
or actually, I used its predecessor, the M300, which can be found used for real cheap. S/PDIF only transmits 2 simultaneous signals, so you really only need 2 channels. Even if you do use a mixer, all of your inputs will be bussed to 2 channels out anyway. With the M350, you can send 2 channels to the line ins, hit the bypass button, which takes all of the FX out of the signal chain, and sends it by S/PDIF out. That way, you can use any preamp or any mixer you want to. With AD-DA delay of less than one millisecond, it's at least as fast as any digital mixer or preamp you could possibly afford, *and* it's not a bad FX box. So if you happen to need a deesser, or slapback, delay, reverb, even rudimentary compression, you also get that. Hell, you are talking about mixer preamps anyway. You could combine this with a dirt cheap preamp, such as:
http://www.8thstreet.com/product.asp?ProductCode=10658&Category=Audio_Processors
and get sound as good or better than most mixers. Or you could upgrade a little, and use it with:
http://www.8thstreet.com/product.asp?ProductCode=10268&Category=Audio_Processors
and get *better* sound than most mixers. It could also be used with any preamp or mixer you have lying around. I have used the older M300 extensively in this role, and I know it works. Good luck. Minor issue- with analog input, it only puts out S/PDIF at 44.1 kHz, but that's entirely usable, and we *are* talking about very affordable units.-Richie