I would suggest that depending on budget the Headroom Millett might make a great office rig, hey wait, that's what I use! It's footprint is rather small (7"w x 9"d x 5"h w/ tubes) and has nice things like 2 switchable inputs (great for compy and DAP), crossfeed and preamp outs (for speakers). I can't believe I waited as long as I did to move mine into the office. Even with the desktop PS it still doesn't seem any bigger than the PIMETA that I had there before because the footprint is nearly the same. Also, the Millett does a wonderful job of masking crappy sources like lossy MP3's but can resolve enough detail to sound excellent when called upon. After a marathon session in the office today (14.5 hours ) I know that I couldn't have made it through it without the Millett and the HD600s.
That's my 2?,
Nate