I noticed the Fuji film make instant film for 4x5 plorarid back. Fuji FC-100c film? Anyway, I have a Polaroid 545I back, but it is completly worthless for whats left in film choices. What would a back that that I could look for in used arena for my 4x5? I have a Omega View 4x5.
There is much less 4x5 instant film available now than there used to be. The two peel apart films that I am aware of are Fuji FP-100C colour film, and FP-3000B black and white, but I think that those are both only available in 3.25x 4.25 and wouldn't work in my old Polaroid film holder.
There is a group trying to bring back a version of the Polaroid type 55 film, you can follow them here: http://new55project.blogspot.com/ but I don't think that they have anything ready for prime time yet.
You can use a Polaroid 405 adapter or a Fuji PA-45. Either one will use the Fuji 100C or 3000B film, giving you an image size of 3.25" x 4.25" I'm quite fond of the FP 3000B film. It's fast, very fine grained and has a good tonal range.