You'll lose the rear footrests and need a set of Superlight hangers (Bolt straight on).
Some companies make "extension kits" that allow you to mount the original footrests on the outside of the cans but I reckon they look more than a little poo. I guess it's down to personal preference plus finding the extension kit...
More info and pictures here
http://speedzilla.zeroforum.com/zerothread?id=41425 They appear to be for SSies but I'm sure you could do something similar with the better looking early SSs....
Darren