You can still get some fresh limited-edition (or last-run) type 80 film from Lord of the Lens.

If you bought the new Polaroid back, it will take either type 80 or 66x film (or Fuji equivalents) - the 66x film is still in production with the exception of 665, and is available from some camera stores if you look around and from Polaroid directly (make sure you DO NOT get the 4" x 5" kind - type 50 in Polaroid lingo but a little confusing from Fuji - that's for a different class of Polaroid back).

(By coincidence I was looking into this back the other day myself. I've also bought a Polaroid 250, which takes the 66x film, so I've looked into availability of that, too )