Have just checked my supplier (very reputable) - they don't have any!
There are a few on ebay that make cables to length - could be worth trying or just order a 10m one and cut/recrimp as you need.
It may not be a perfect way to do it, but you could use 4pair cut two pairs off and then use heatshrink sleeve over the end to seal it and reduce the OD to fit the connectors. Have often seen it done that way.
The older BT data extension kit was based on 2pair - so if you know any BT Techs you might be in luck scrounging a length.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
M H C
taurus excreta cerebrum vincit