Home defense and concealed carry in the same gun...maybe start him on a Ruger LCR-22 then see if he can handle the LCR-38.
If that stings too much, perhaps try a steel-framed S&W J-frame, Model 36 or 60 in .38 Special.
If the .38s are too much, back it down to the 8-shot, 15-oz LCR-22. That should be fine for him.
If you want to get esoteric, you could see how well he handles .22 magnum and/or the vast variety of power levels available in a .32 caliber.
Those are the only real revolver choices between .22LR and .38 Special. The .32s are hard to find, though.