Changing to 'cafe' bars will change your riding position considerably.
I would be inclined to go for a set of clubman bars that can be mounted in the existing risers.
If you find that you do not like the lower riding position, this will be easier to change back to stock.
These would be my choice of adjustable bars:
http://raask.com/e4.jpg
Mounting clip-ons will require either modifying the headlight mounting tubes or dropping the forks in the triple trees and mounting the clip-ons above the trees.