You've run into the eternal .380 conundrum, bro. If you go with FMJ for penetration, you end up with ball ammo that has been producing narrow little icepick wounds and earning the .380 a reputation as a sub-par man-stopper for over 100 years; if you go for expanding bullets, you risk a wound track that doesn't get deep enough.
My best advice would be to turn the page in the Kel-Tec catalog and scale up to their little single-stack 9mm, or the new Ruger equivalent (LC9), or other micro-9mms like the well-proven Kahr PM9 or its surprisingly nice little economy version, the CM9 introduced this year.
If I had to carry a .380, I'd consider the Buffalo Bore load you mentioned (though I don't know of any actual shootings with it, its flatter nose SHOULD do better than round-nose ball for tissue disruption, though you can't expect miracles), or as a middle ground a slowly expanding .380 JHP like the Hornady XTP.
The question is, do you really HAVE to carry a .380?
Wishing I'd had better news for you,