Depends on what you plan to do with it. A lot of people like Fuji FP-100C for color proofing. Polaroid type 665 is B&W positive/negative film. You can go to www.polaroid.com to see what each film they make does. You want to look at the 3.25x4.25" pack films numbered 6xx (except for 600).
If you want to use it to check exposure, run some tests with the films you're actually using before trying it with anything too important. In the studio with strobes, it's pretty reliable, but if you're using it for longer exposures, you'll find the reciprocity characteristics to be very different, not only as regards exposure, but also color shifts with longer exposures.