I have two 3x4 Speeds, a Pre-Anniversary with a Graflex back (takes the slotted holders) and an Anniversary with the spring back. The nice thing about the Graflex back is that I can use a bag-mag, which takes 12 sheets of film. I have only two slotted holders, but I also have two roll film holders, which I can also use on my 3x4 Graflex SLR's. For film, Ilford does have 3x4 available, along with other sizes, once a year. You might check with Badger or other dealers to see who has it available. It is a special order once a year, not cheap, but at least we can get other emulsions than the Efke 100 speed stuff from Freestyle.