Hello, this is my first post on the website, I suscribed because I want to purchase a crown graphic for making portraits. so I'm looking on ebay....

Well I've read a lot of stuff about the polaroid back for this camera but as I'm a little bit stupid I still don't get to understand the whole thing:

There are polaroid backs and fuji backs, the fuji is much lighter and newer, the fuji takes FP-100c or FP 100c45, the FP-100c45 take bigger images(?) but is more expensive than the FP-100c....I feel I'm missing something, right?

Which back do I have to take?