Recommendations for a good audiophile digital coax (BNC-BNC) 50 ohm cable?

Needed for a connection between DAC and clock. Most good cables out there are 75 ohm, and the 50 ohm coax cables easily available are mainly for video, with clearly poor insulation, cable quality and solidity (albeit very cheap! :-). It is my understanding that using a 75 ohm cable for this connection might be OK for extremely short distance (1-2 ft) but for not recommended for "normal" use (1 m or more). Was wondering if I missed something?