Parts list for the Sora Dahon Jack road conversion spreadsheet (Dropbox public link) - https://dl.dropboxusercontent.com/u/...20black%29.xls

Come back to me if this link does not work. Obviously the weblinks/prices are based re UK sources/£, but it will give you an idea.
Additionally re the crankset - I would pay extra and go to a full Sora crankset (inc BB) if you can - Just one thing less to worry about.

Disclaimer -> I hold no responsibility if your adventures go bad! But I would like to see pictures if it all works out ok!