In the S&W line, it's 'N', then 'L', 'K' and 'J' in decending order of size. As far as grips, etc. go, the 'L' and 'K' are virtually identical.
The S&W 'K' frame's ergos are about as close to 'universal' as they come. The 'L' models add a bit of beef to the frame to hold up better with extended use of higher-intensity .357 loads.
The Ruger GP-100 series of revolvers might be particularly well-suited for your needs. They have no 'grip frame' per se, and are capable of being fitted with grips of almost any configuration you might need. They also have a 'push-button' cylinder release in the left recoil shield which may be easier for you to manipulate. They are, as most Ruger revolvers have traditionally been, somewhat larger than they need be for the task, but they are also extremely rugged. They are heavier than they need to be for the cartridge, IMO, but that makes them easier to shoot comfortably if more of a load in the holster.
Hope this is of some help.