Oil coolers seem to be a bit of a rareity - I remember looking when I was thinking of fitting a second cooler to my big bore 900SS.
You could try
http://www.reservoircogs.com or the dreaded Ebay
- (search Germany and the USA as well !!!)
Demon tweaks also sell nice looking after market coolers if I remember right but they were VERY expensive...
http://www.demon-tweeks.co.uk/catego...asp?cls=MCYCLE cooler:
http://www.demon-tweeks.co.uk/catalo...&fro m=search Starter motors....
Erm - I actually have a spare one but sadly, I think I need to hang onto it given all the starting probs I had at the end of last year.
Not sure of the differences between models - but they are just as rare on Ebay as oil coolers but, one did crop up about a month ago.
Check out my threads on breakers - you might get lucky !!!
Cheers - Frank