In the ~$2,000ish range, I would look at asynchronous USB 2 24/192 DACs with balanced ins/outs. In this range, I would recommend that you evaluate the Grace Design m903 - $1,895. I own the m903 and I think that it is an elegant design and user interface that sounds great and the company is great to deal with. It is their 3rd generation product and they are a pro audio company who's product quality is excellent. The asynchronous USB audio code was written by Gordon Rankin of Wavelength Audio.
Two useful reads:
http://www.gracedesign.com/support/whitepaper08.pdf
http://www.gracedesign.com/support/m903_manual_RevA.pdf
My $.02






















