I'd also take a look at the Beresford DACs. They like the Zero DAC, it accepts multiple digital inputs, selectable on the front of the DAC. The older 7510 can accept 2 Toslink and 2 Coax inputs. The newer 7520 has 1 Toslink, 1 USB and 2 Coax inputs. There is a fairly large DIY mod discussion group for this on The Art of Sound forums, where Stan, the designer of these DACs also frequently contributes.
Also has built-in headphone amp and volume control (should you want to forgo a preamp).
Lastly, MCM Electronics is also selling a rebadged version of the 7510, which can often be found for $79! Google "$79 DAC" to find the discussion thread that often includes the most recent coupon code to get you that $79 price.
Haven't tried other DACs, but really like the difference the MCM DAC made to the sound of CDs from my Oppo DVD player. Since I will also be using optical output from my MacBook, the ability to easily select sources was crucial for me.