Putting the PC in the listening room is sort of similar to one of my setups. I have a laptop behind a wall connected by USB cable to a device that converts to SPDIF and then to a DAC. The noise of the laptop and its USB attached hard drive is slight and fairly contained anyway but it could definitely be an issue.
I have come to some conclusions about USB audio as a result. Resampling w/ Foobar requires a fast processor to avoid pops and clicks and at least in my system, utilizing a three year old and therefore slower processor has not been a good trade off. The playback sounds choppy w/o resampling but colored with it. Resampling has a definite "character" and it may not be to your taste. This is similar to the non oversampling DAC debate you encounter on these boards. Ultimately, while I can't personally attest to it, very good, maybe even pop free reproduction is available this way.
I have another system in my bedroom w/ an almost stock SB3 and I decided to throw out the DAC in that system in favor of the SB3's onboard BurrBrown. This a SET based system and has a beautiful tonal quality at least to my ears. The SB3 fits in nicely here and has been utterly foolproof.
I had an SB3 in the living room system but sold it to Mark in Canada because I felt that I heard better quality w/ the USB based system. The resampling can be very seductive at first, more air, inner detail, the "Wow, listen to that, I never heard all that before" factor that influenced me. But add in the annoying pops and constant messing w/ the PC and I'm changing my mind again.
I suppose a new, faster PC might eliminate the pops. That's a sizable outlay and my present laptop works w/o issues when using Slimserver. The Slimserver software player doesn't require anywhere near the resources that are needed for Foobar. At the end of the day, when you throw in the convenience factor w/ the SB3, it just makes it a better choice.
Hope this helps.
BTW: Steve Nugent of Empirical Audio was terrifically helpful and his site has some good stuff re: USB based audio.