Sorry Squishy, I'm an EX Bandit 600 guy, so I have no idea what length a stock Bandit 400 shock is. Maybe one of the 400 guys has a spare shock they can measure.
As for GSXR 750 shocks, again based on the chart I referenced, the 88-91 as well as the 92-95 shocks are all 312 mm, eye to eye. I ASSUME the 88-91 have a remote, hose mounted reservoir, and that the 92-95 likely have the reservoir integrated into the shock body, which can make it harder to mount, but I DON'T actually know.