We use this:
http://www.jameco.com/webapp/wcs/sto...oductId=232995
for switches and other digital inputs requiring only 2 conductors.
And this:
http://www.jameco.com/webapp/wcs/sto...oductId=233023
for Pots and other stuff requiring 3 conductors.
You can get similar ribbon wire to the IFI stuff on ebay and at hobby shops, they often call it "servo wire", but its cost is far more than the belden stuff from Jameco. We haven't had any noise issues that would have justified going with a ribbon-style wire instead of the multiconductor cable.