For your USB extension, check out this optical cable:
http://www.usbstuff.com/opticis.html
I use a 65 foot optical usb extensnion with no loss or degradation of the signal.
If you are using a PC, the following ASIO driver is superior to the ASIO4ALL
http://www.asio2ks.de/index.html
Using this driver, I have no pops or ticks with the Cosecant. The settings on J. River and Foobar are minimum buffering.
I hope this helps you,
Steve