From what I understand, those Keces DACs don't have a USB connection, so you plan to use them with an onboard sound card?
While the difference between them may be genuinely small and perhaps even nonexistant, I'd get the (proper) ESI Juli@ and rest assured that you're getting good quality, instead of using a low-quality onboard sound card that probably has something wrong with it.
Also, the Juli@ has nice drivers. If you also want to use your computer with speakers using a speaker amplifier and it has optical or coaxial, you can use the Juli@ for both phones and speakers without even doing any software switching. The software has a feature to monitor the digital output, which allows you to send the same signal to both your phones and speakers, even in Vista.
Apart from that, the Juli@ may be internal, but it is, at least with my setup, completely distortion free.
All it suffers from is crashing my computer when I go to Hibernate, but YMMV.