Speaking for myself, I prefer the Airweight series to the titanium revolvers, like the AirLite 337PD. The aluminum and steel combination in the Airweight series makes the gun light enough for easy pocket carry, without making it so light that +P loads recoil excessively and just makes it too uncomfortable.
Everyone's interpretation of recoil is subjective, so YMMV. But if I were you, I would fire off a box of 50 158gr +P loads in a 337PD if you can and see how you like it compared to a 642 or even a steel framed revolver such as the model 64. For me, the 642 is as light as I would want to go. I find that a lighter revolver makes me not want to practice as much, or use weaker ammo than I would normally carry.
As far as the .380s go, I prefer the .38 special +P over it all things being equal. But I have to say that there are applications for which I cannot pack even the small J-frame. For those times, the little Ruger LCP fills the niche nicely.