Hey guys,
Jumping in a bit late on this one, but...
There are a few really nice Ti forks out there that will do well with canti brakes from some custom builders...however, Ti is just not a material that is best suited for fork construction in a single crown format, let alone with disc tabs, atmo.
I think you are spot on looking at a steel fork that is geometry adjusted to fit your frame.
I would suggest providing a atc length of 15 7/8" or 403mm an excellent fit for your frame as it was designed around 63mm sussy forks.
There are many configurations you can choose for your fork construction;
Unicrown - lightest weight
Fat style - excellent tracking with moderate absorption
Box crown - a little heavier but oh so classy
Standard lug and blade - nice and plush, but not a style fit for your application.
I just fabbed up this baby yesterday...a crown forward Yo style fork and custom stem...
cheers,
rody