127 film sources on the web:
B&H lists Kodak E100G slide film in stock now.
Film for Classics shows Efke 100 B&W film, and Kodak Portra NC for color print, and E100S for slides in stock.
Frugal Photographer lists Macophot 100 B&@ film, Macocolor print film, and Macochrome UCR slide film. I think this outfit also stocks the "superslide" mounts needed for projecting 127 slides in a normal 2x2 projector.
J and C lists Efke 100 B&W film and Macocolor print film, but notes that production of Macochrome has stopped and only limited existing stocks are available.