I too am a paraplegic and as such have little use of my left leg and virtually none of the right.
To that end my SE5 has been fitted with hand controlled braking. This was done by the dealer where I bought my bike and I believe that a lot of the parts are from Triumph.
A lever with a fluid reservoir has been fitted to the right handlebar and looks like it belongs there. This operates a slave cylinder mounted behind the brake pedal facing forward.
This in turn operates a clevis which straddles the lever attached to the brake pedal. This has the advantage of making no modifications to the original braking system.
I have had my bike since February and have done some 13,000km (8,000 miles) and have no problem with it whatsoever.