Cantilever Cable yoke

Hey all,
I have just been having a bit of a read up on Sheldon Browns ideas on
cantilever brakes. My set up is currently Avid Shorty 6 calipers and
shimano ultegra levers. Am I better off using the shimano A or C type
straddle wire, or would i be better off buying an old fashioned two
piece yoke? Would the latter provide more scope for adjustment.

(The brakes are currently off the bike, and I managed to totally f*** up
the existing C wire the other day (see late night maintenance threead!)

thoughts please...