I have a Sinar F 4x5 and I shoot mostly portraits. I like to shoot a roll of 120 in a holga during shoots for memory's but thought it would be fun to have a polaroid back to do the same. Are there any options that take film that's still relativity easy to get? I found a variety of 2x3 films on B&H but I have no idea what I can load into a polaroid back or if there are different types of polaroid backs for different types of flim. Found a bunch of "Land camera 545" backs but dont see Polaroid 545 film anywhere.