I suggest you canvass the manufacturers that offer hand controls
(rudder stick and spoiler lock) on their list of options, for
organizations/customers that ordered adapted gliders. These include:
Schempp-Hirth (Duo Discus and Discus 2c)
Schleicher (ASK-21)
Allstar PZL (SZD-54-2 PERKOZ - pending?)
I would be interested to learn of other manufacturers offering the
controls.
BTW, Freedom's Wings Canada has trained one para pilot to an
Instructor endorsement at the York Chapter (Toronto).