Mogami Neglex 2534. Low capacitance and inductance, shielded, low noise, right price.
http://www.markertek.com/Cables-Connectors-Adapters/Audio-Cables/RCA-to-RCA-Cables/TecNec-Cables-Connectors/MSC1-5RR.xhtml
Scroll down for the lenght you want. I am using the same cable (mine is DIY with Cardas Rhodium connector) on my preamps with great results.
http://www.markertek.com/Cables-Connectors-Adapters/Audio-Cables/RCA-to-RCA-Cables/TecNec-Cables-Connectors/MSC1-5RR.xhtml
Scroll down for the lenght you want. I am using the same cable (mine is DIY with Cardas Rhodium connector) on my preamps with great results.