Great link (the GD). All the info you need to see without a lot of crud.Gold Dot SB or Hornady CD should do the trick. Full mag loads in the 2.25" are brutal, but since it's for SD use, I'd go with one of those over 38 SP+P.
Buffalo Bore makes several 357 and 38 SP+P loads that would get my vote also.
Three dirt bags with one shot? I'm down with that. Just think, my low capacity SP101 could stop 15 aggressors....cool.As long as you stay away from heavy hunting loads that will blow through three people, you would be hard pressed to find a bad load for self defense in .357 Mag.