Finally found Empire chicken fat here (in the frozen foods section). There was a tag on the display saying "Customer request"--I don't know whether that means they've just started carrying it, or if they don't have it all the time.
Prices are 10-15% higher than other grocery stores but it's a great place for brands the other stores don't carry.
Just wish it was closer--it's the complete opposite end of town for me.
(I know they're conserving electricity, but some sections of the store are really dark. Replacing some of the spot lighting with floods would be better.)