Unless you are going to shoot a lot of panoramics (6x12) it would probably be best just to crop down 4x5 sheet film. If you want to use one of the 6x17 backs you will need to get a graflock backed camera as others have suggested. If you have wood working skills either a Chamonix or a Shen-Hao back could be made to work on my Nagaoka (same camera as yours I think), though it would be easier to just purchase one of these cameras to start with.