I have not heard the DACs you are interested in. Have you checked out.
http://www.computeraudiophile.com/Lots of information on DACs.
Also extensive reviews here:
http://www.digitalaudioreview.net.au/I use an open box Tranquility DAC and see no reason to look further at this point. It seems equal to my Decware gear. Cables up the price though, and good cables matter.
With Decware amps and speakers, it becomes quite clear that the source is super important. It is the beginning of the sound and if it degrades the music from the onset, the amp and speakers will definitely reflect this.