I have a '73 (I think?--block lettering, capella lugs) supercourse frame. It takes a 68mm English threaded BB (pretty standard--not the proprietary version). The length of the spindle will depend on your crank and the chainline you're after, but the spindle on mine is 113mm for a single ring up front and a fixed cog in the rear. This gives me roughly a 42mm chainline--not sure if this is what you're after with the Nexus hub in back, though.

I don't think there's any reason to spend that much money on a BB. This might be blasphemy but I've used the nashbar square taper BB with success (http://www.nashbar.com/profile.cfm?c...tom%20Brackets)
They'll probably have a sale soon (as long as the sun comes up in the morning and goes down at night).

Unless you're looking for a BB that will outlast the life of the bike, this should work.