for info on disabled bikers, and adaptions have alook at these guys,
National association for bikers with a disability http://www.nabd.org.uk/ ok their a UK based charity group. but are well up on adaptions, and would probably answer any questions you might have on their forum
http://forum.disabledbiker.co.uk/index.php
Their online open house magazine has features which may be of interest to you.
it contains features on auto clutches, and there numerous suppliers that have parts suitable for specific disabilities, such as swopping brake/clutches/throttle to the oposite side.
Peirre
NABD supporter