Circles

Thanks for the advice, much appreciated. I will go for shorter arms, probably suginos or the campag pista.

One note, for square taper BBs there are two standards - ISO and JIS, JIS is much more common and readily available. The Sugino 75s ideally use the less common ISO standard although you can get them onto a JIS BB, but they do not go onto the taper a far as they would on an ISO taper - so you will get a less predicatable chain line and - I guess - the interface will be less stiff (?)

Anyhow all this could be moot as I do not know anything about your frame, the rear spacing and so on.

One more question, does the BB length very much depend on the rear hub - I'm running a white industries eccentric eno.

Yes, you need to work out the effective chain line of your rear hub and factor this in when you get your BB/cranks.

You can do this with a ruler.

One final point is that the cog/freewheel you choose will vary in it's position on your hub - which doesn't help !