Streaming or long interconnect for better sound?

I'm planning to use my iMac as a music server. The music is all in the Apple Lossless format.

I'm thinking of either (i) getting a USB DAC and use a long (15 ft) interconnect to hook it up to my integrated amp (Musical Fidelity A3.2) or (ii) stream music from the iMac to an Airport Express (AE) and connect it to an external DAC with an optical digital cable. As a DAC, I'm leaning towards the Musical Fidelity V-DAC.

While the AE solution is certainly more elegant, would it also sound better than the long interconnect option?

Thanks in advance.