I agree with arafiq. The DAC built into the Parasound P5 seems pretty impressive, and I don't understand why the OP would want an outboard DAC for $ 300. You'd probably need to spend a significantly higher sum than $ 300 (plus the expense of another IC cable) to improve on what's already in the P5.
From the Parasound website description of the P5 .....
"Burr-Brown PCM1798 DAC with USB, Optical and Coax inputs
Coax and optical accept all sampling rates up to 192 kHz, 24-bit
USB accepts up to 96 kHz, 24-bit
Incoming jitter on all three digital inputs is significally attenuated with an effective clock recovery system"
From the Parasound website description of the P5 .....
"Burr-Brown PCM1798 DAC with USB, Optical and Coax inputs
Coax and optical accept all sampling rates up to 192 kHz, 24-bit
USB accepts up to 96 kHz, 24-bit
Incoming jitter on all three digital inputs is significally attenuated with an effective clock recovery system"