this one at least should work for the 60D, and perhaps later for 70D
http://www.ebay.com/itm/USB-10Pin-to-3RCA-AV-Stereo-Cable-AVC-DC400ST-for-Canon-EOS-7D-60D-60Da-70D-600D-/381494228857?hash=item58d2d3f779:g:IB0AAOSwUdlWcmYH
http://www.ebay.com/itm/USB-10Pin-to-3RCA-AV-Stereo-Cable-AVC-DC400ST-for-Canon-EOS-7D-60D-60Da-70D-600D-/381494228857?hash=item58d2d3f779:g:IB0AAOSwUdlWcmYH