Is this an item I can pick up from an auto parts store, or should I stick to an authentic Cummins part?

I need to make the jump eventually, as I can now pull my fuel pressure down to zero if I try.

 

You'll need a regulator with that pump, but I don't see why one from one of those places won't work. I'd think the pee pump guys may be the better crowd to ask, as they would be the ones who may have tried an autozone/napa/checker brand pump.

 

I'd just stick with good ol' genuine Cummins. Can't go wrong. That's just my preference.