The odds of getting factory .41Magnum ammo at a price that does not make you whimper and cry are very low. Maybe an estate sale if you watch out for one. I got a bunch of ammo in my favorite calibers during a period roughly 5-10 years ago and should be ok. I am also doing more to save empty cartridge cases for potential reloading after I retire/move.
As for bullet types: I would not bemoan the prevalence of the SWC types. As a rule, I have gone full reactionary, and almost all of my revolver ammo that is not also in a pistol cartridge (such as 45 ACP) is SWC (or WC, in .38 Special). In the auto-pistol calibers, I prefer to take advantage of the research on service ammo since the mid 80s, and I tend to go with Doc Roberts' advice. A heavy for caliber SWC in most medium to large revolvers will perform adequately well, with any needed performance variation addressed by picking a decent velocity for your purpose.