Hi Raf
What bike are you thinking of putting Billies on?
They come back quite a bit, so if your bike wasn't necessarily designed for upright bars with a long front end(like current Rivs), you may run into problems with bar end shifters.
I put a set on my 96 All-Rounder, and kept hitting my knees on the bar end shifters. I switched to thumb shifters, because I love the extra hand positions with the Billies over the Albatross bars.
Jim