I suggest the .44 because of the larger selection of off the shelf ammunition choices. It is easier to find a mid-range load in .44, (.44 special) which will be better suited to self defense. Remember, the main reason the .41 never caught on with the police, was the lack of a mid range self defense load.

If I were looking for a large bore self defense revolver I would look at a model 625 (.45 ACP). They can be had in barrel lengths of 3, 4, and 5 inches, and the .45ACP is specifically a self defense round. Lots of good self defense choices out there, Hornady TAP, or Speer Gold Dots, and many others. If you ever had to use the .41 or .44 with magnum loads in a self defense situation the muzzle blast and noise would be a major drawback. If that self defense situation took place indoors, the noise and blast would be much worse. Unless you are in big bear country, the 625 would also work well as a woods gun.