Some bents are far more adjustable than others. My Rans Stratus is one of the most adjustable bents out there. The seat has a great range of fore and aft adjustment, and angle of the back also. Then the "chopper" handlebar is the most adjustable set of bars out there.
BTW IMHO I think a LWB bent is probably the easiest to adjust for medical conditions, and easiest to ride.