Does type 55 come in 4x5" packs? If it does, I don't think there's an easy way to remove shets from a pack for processing later. I don't see it on Polaroid's website:

http://www.polaroid.com/products/pro...ll&sc=Packfilm

You can get a 545 holder used for around $100. I'd just get one and use sheets, if you want to shoot type 55 in 4x5".