There's "+P" and then there's "OH MY GAWD PLUS PEEEEEEE"!
The mildest "+P" will be the 158gr LSWC-HP (pure lead hollowpoints, no jacket) as made by Federal, Winchester or Remington. They are effective in that order and a lot of people seek out the Remmies. Two even more potent loadings exist involving 158gr lead hollowpoints - you'll find old-stock Cor-Bon and the new Buffalo Bore variant. Those are both pretty wild, but your gun can digest a healthy diet of the Remmies or Winchesters.
We know that in 357Magnum, the lighter 125gr jacketed rounds are actually nastier on the gun than the heavyweights like the 158s, even when the power level is the same and both are jacketed. That's because the lighter round accellerates faster and hits the forward edge of the cylinder and back of the barrel harder than the heavies.
There's reason to think the same will carry over to 38spl, esp. since the plain lead rounds work well in that caliber as they're not driven fast enough to fly apart like they would in 357.
If you're of the opinion that you should do a lot of practice with your carry load, and I personally question that view but it IS popular and has some merit, then I think the Remmie 158+P lead hollowpoint is the way to go in that gun.
If you do NOT hold to that view, if you think (as I do) that your own body's changes under stress will overwhelm any difference in felt recoil and that you might as well get the gun handling down pat with lesser (cheaper) practice loads, then use pretty much anything you want for carry and a small portion of your practice (a cylinderful at the end of your shooting sessions). The newer Gold Dot 135gr +P is a damn fine round or go whole hog with those Buffalo Bores or the Cor-Bon 110gr or 125gr +Ps, all of which are pretty crazy.